Paperwhites for the California Holidays

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In comparison to the vibrant color of many indoor holiday plants, the white or white-yellow blooms of Paperwhites (Narcissus species) might seem plain, but when planted closely in pots to provide massed bloom, they provide a stunning compliment to the richer colors of Poinsettias and Amaryllis (see Indoor and Potted Plants for the Holiday Season). And unlike most other plants traditionally grown for indoor holiday display, Paperwhites can be planted outdoors in warm-winter California areas after holiday blooms are spent, where they naturalize and can bloom again year after year.

Paperwhites are native to the Mediterranean, which is similar in climate to much of California, with cool or cold rainy winters and warm-to-hot, dry summers. Unlike most Narcissuss species (such as Daffodils), winter chilling isn’t needed for Paperwhites to thrive and rebloom outdoors in warm-winter California gardens.

September through November is the time to plan ahead for indoor holiday flower displays. Paperwhites need about 4 to 6 weeks to bloom when grown indoors. Many options are available, including variable height, and more-fragrant versus less-fragrant varieties.

Are you too busy to tend indoor plants during the holidays? Vendors make it easy to grow Paperwhites, which are often sold already planted in pots or in kits that require almost no effort other than watering. Bulbs can also be grown in plain water, or in a glass vase or container with a decorative medium such as small polished stones, marbles, or sea glass, provided that water is changed every few days.

When grown indoors for holiday blooming, space bulbs closely, about 1 to 2 inches apart for a dense mass of blooms. Indoor holiday Paperwhites will bloom best and remain healthier in bright indoor light, preferably direct sunlight through a window for at least a few hours per day.

If you’re planning to plant Paperwhites outdoors after the holidays, deadhead to remove spent blooms. This prevents the bulbs from expending energy forming seed pods. Paperwhites are frost sensitive and best planted outdoors during warmer periods with daytime temperatures of at least 60° to 70°F. Plant bulbs in an area that receives at least a few hours of direct sunlight during winter, about 6 inches deep, and spaced at least several inches apart. Over years, bulbs will multiply, fill in, and may need to be dug up, separated, and replanted every few years to optimize blooming.

Top dress after planting with compost, and water to maintain moist soil during dry periods between winter rains. Bulbs will benefit from added phosphorus and potassium when soils are deficient or soil alkalinity is high.

Paperwhites may go dormant in response to mild frost, and may be killed by periods of hard frost. Sufficient sunlight and healthy leaf growth from winter through late spring or early summer will help bulbs to store energy for repeat blooming the following fall or winter. Like many California natives, Paperwhites have a dormant period during summer rather than winter, often beginning late spring or by midsummer in response to hot temperatures. Reduce to minimal and occasional watering as leaves die back and while Paperwhite are dormant until new leaf growth is seen from late summer through fall.

Other articles with holiday interest:

Poinsettias: Tips, Care and Fun Facts for the Holidays

Indoor and Potted Plants for the Holiday Season

 

 

 

Citrus Trees: 5 Things to do Before Thanksgiving

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By C. Darren Butler and Ann Clary

For gardeners lucky enough to have citrus trees, fall is a time of anticipation. Citrus trees may be bulging with full-sized but unripe fruit. It may seem that the fruit remains green and unripe month after month – because it does! Unlike most temperate fruits, citrus may need several months to ripen.

Make the most of your harvest and keep your trees healthy by following these five simple tips. For early varieties, you might be harvesting home-grown oranges, lemons and grapefruits by the middle of December. Sweetness of citrus fruits improves if they’re left longer on the tree.

 

  1. Rinse citrus leaves. After months of summer smog, ash from fires, and other pollution, citrus leaves need a shower. This gritty layer of silt and dirt on citrus leaves slows or inhibits the trees’ ability to perform photosynthesis. Trees need a lot of energy to ripen fruits, while pollution on leaves may limit how much sunlight they’re able to “eat.” So take out your garden hose and wash away the grit. Don’t worry if you can’t clean off every leaf – just washing off a portion of leaves will help your trees.

 

  1. Acidify your soil with vinegar. Citrus trees generally prefer soil pH at about 6.0 or below. Iron and other nutrients become decreasingly available to trees when soil pH is above 6.0. Citrus trees tend to develop nutrient deficiencies at pH of 7.0 and above. Soils in Southern California are naturally alkaline, and watering over years with alkaline city water only makes them more so. Acidify your soil by adding 1/3 cup of vinegar to 2 gallons of water used as a soil drench after regular watering. Most trees will benefit from this extra acidity at least twice per month.

 

  1. Remove mulch from the area immediately surrounding the trunks of citrus trees. Mulch may shift around during windy weather or be moved by the blowers of many a city gardener. Fall before rains is a good time of year to doublecheck that mulch hasn’t migrated toward tree trunks. Mulch traps moisture against tree trunks and major roots, and may encourage root rots, crown rots, and other diseases. Clear an area with no mulch and bare soil only around tree trunks to a minimum 6-inch radius from small tree trunks, and 1-to-2-feet or larger radius from the trunk for established and mature trees.

 

  1. Monitor water needs. After the heat of the summer, many gardeners cut back on water in their yards. However, citrus trees still need regular, deep watering (usually every few weeks for established trees) while fruit is ripening. Slightly curled leaves on citrus trees usually indicate that trees need more water. If leaves are folded almost in half or drooping, this may indicate serious drought stress. Flat citrus leaves generally indicate that a tree is adequately watered.

 

  1. Apply a minimal amount of a balanced fertilizer formulated for citrus trees or fruit trees. Citrus benefit from rich acidic soil. In most yards, they need regular fertilization about every month or two for optimal growth and yield. If you aren’t fertilizing regularly, do so at least once when citrus are budding and blooming, and again after they set fruit. Encourage a productive harvest by applying a small amount of a balanced fertilizer, generally with reduced nitrogen while fruiting. Beware: applying too much nitrogen will promote foliage growth at the expense of ripening fruit. Dr. Earth Fruit Tree Fertilizer is an excellent fertilizer formulated for fruit trees.

 

Other articles of interest relating to fruit trees:

Why are Leaves Curling on My Orange and Lemon Trees?

Intensive Planting for Citrus Trees: GardenZeus Advanced Tip

Citrus Leafminer: Serious Pest or Aesthetic Irritation?

 

Join Darren for a Discussion of Fruit Trees on this Gardenerd Podcast

Are you planting fruit trees correctly? Concerned because your peach trees and plum trees aren’t consistently bearing fruit? Having problems with pests and diseases that return year after year? These topics and many others are discussed in the September 5, 2019 Gardenerd Tip of the Week Podcast with guest expert Darren Butler, who is interviewed by Gardenerd Christy Wilhelmi. Christy is also a GardenZeus Advisor.

See the Gardenerd.com page for the Sep 2019 podcast interview with Darren Butler or listen directly to the podcast.

Other articles of interest:

Protecting Your Citrus Trees: Sunburn and Garden Tools

Growing Orange Trees in Containers: Meeting the Challenges

Planting Citrus Trees: Proper Planting and Long-Term Health

Bougainvilleas: Essential Pruning and Maintenance

GardenZeus receives commissions for purchases made through links in this post. There is no additional cost to you.

by Ann Clary with C. Darren Butler

What makes bougainvilleas so appealing to gardeners around the world? Undoubtedly the profusion of colorful and long-lasting flower bracts, the specialized leaves that are often mistaken for blooms or petals. In Mediterranean and mild-winter California areas, bougainvillea are a signature landscape plant, offering their profuse displays in a range of colors including pink, purple, magenta, white, yellow, orange, and red. The true flowers are small and inconspicuous, white or cream colored, and nestled within the colorful bracts. Bougainvilleas are much loved for their exuberant and lasting display of summer color at a time when many other plants are suffering in the Southern California summer heat.

Bougainvillea plant cascading over wall

Bougainvillea plant cascading over wall

 

Pruning. Bougainvilleas produce their flower bracts or “bloom” on new growth. Frequent or at least annual pruning is important to encourage new growth that will produce the colorful bracts. Overgrown, neglected, enormous, thorny bougainvillea shrubs are a candidate for the worst-ever pruning nightmare. Older bougainvilleas tend become dense as dead leaves, spent bracts, old twigs, and other plant matter accumulates to form thatch within their twiggy interiors. Neglected bougainvillea may produce unwanted conditions such as taking up too much space, becoming difficult to manage and prune, becoming too large or heavy for supports, providing an almost-unassailable home for rodents, and losing their colorful and attractive appearance. The dense inner woody twigs and branches take up space and lack aesthetic value—and they don’t produce the lovely bracts.

It is particularly important to prune bougainvillea regularly to maintain reasonable branch structure, keep them manageable, and avoid tall, heavy, and/or unruly shrubs that put out little new growth each year and bloom only occasionally or minimally. Bougainvillea naturally produce many main stems that can become a tangle within just a few years. Vines can be pruned at almost any time of year except during periods of hot weather or frost.

Don’t hesitate to cut back larger, older stems as needed for good structure, or to provide a hard structural pruning every few years. Frost-free periods from winter through early spring when plants aren’t actively blooming are ideal for major pruning. Reasonably skilled structural pruning is important for bougainvillea. Hire a professional or take the time to learn proper structural pruning.

Simple pruning involves removing snipping here and there for shaping, cutting back generally to encourage new growth, and removing unwanted stems to encourage whatever permanent form is desired. To train your plant into an espalier or to direct it to grow and bloom in a specific location, attach selected larger branches to support and remove the smaller branches growing in the wrong direction. If you want your bougainvillea to grow on a fence, weave small and young branches throughout the links or open spaces. Remove or redirect uncooperative branches.

Trunk of old bougainvillea plant

A tangle of main stems on old bougainvillea plant

 

Mature bougainvillea plant with interior thatch

Mature bougainvillea plant with interior thatch or plant debris

 

Bougainvilleas are one of those plants that benefit from frequent or almost constant cleanup and light pruning to keep them manageable and maintain their shape, including pinching back, light trimming, training, and cleaning up dead leaves and stems. Pinching or snipping off the tips of new shoots is an easy way to shape smaller plants to be more full and bushy, and is especially recommended for shrubby cultivars.

Bougainvilleas naturally follow a cycle of blooming followed by a rest period. Healthy plants that aren’t overwatered repeat this cycle during the warmer and drier parts of the year. Dedicated cleanup and moderate pruning is recommended during the rest period after every bloom cycle.  Monitor or notice blooming to time your pruning during the rest period that follows.

Beware of maintenance gardeners who use hedge trimmers on bougainvilleas unless you want square or round shrubs and hedges! This practice may regularly remove the new growth needed to produce the colorful bracts, produce unattractive views of sheared stems, and tend to maintain bougainvilleas as nonblooming and nondescript green/brown shrubs.

Remember that pruning bougainvilleas can be a dangerous task: they have thorns! Gardeners should tackle bougainvillea pruning with a pair of pruners, loppers, heavy gloves, hat, eye protection, long sleeves and long pants.

 

Soil Amendments. Bougainvillea bloom best during warm weather after several weeks with little or no water and fertilizer, followed by generous watering and fertilizing. Allow dry periods, then fertilize with organic manures, compost, and/or a balanced fertilizer for blooming perennials while also increasing water. Bougainvillea plants will often perform well throughout summer and into fall if fertilized once in late winter or early spring.

GardenZeus has customized gardening information by plant and zip code. To get started, enter your zip code here.

Other articles of interest include:

Bougainvillea: An Ideal Plant for Hot Mediterranean Areas

Constructing a Mediterranean Herb Garden

 

 

 

What To Do in March: 10 Tasks for Southern California Gardeners

by C. Darren Butler with Ann Clary

March is typically one of the busiest months in the Southern California garden. Regardless of whether you live in one of Southern California’s inland valleys or along the coast, here are 10 items that should be on your gardening to-do list this month:

  1. Cut back or replace diseased, leggy, overgrown, unproductive, or troublesome perennials, preferably before new growth begins. Consider adding drought-tolerant plants wherever watering and fertilization can be managed appropriately.
  2. Plant warm-season annual vegetables and flowers. Early-spring weather has been unusually cold and wet this year (2019) in Southern California, so be cautious with starting seeds directly outdoors when temperatures are below 70° F. Many seed varieties may tend to rot before germinating in cold, wet weather, and some may have low germination rates when temperatures are below 80° F. Start seeds indoors and transplant starts outdoors. Start seeds as soon as possible. After a late, cool and wet winter this year, Southern California may have rapid or sudden shifts in temperature to warm or hot weather in March or April that could stress seedlings and make vegetable gardening difficult.
    bean seedlings

    bean seedlings

     

  3. As weather warms, monitor emerging warm-season pests such as snails, slugs and aphids. Despite a generally cool February and March in 2019, most Southern California areas received little or no frost, so larger-than-usual numbers of adult insect pests and eggs may have survived the winter in inland areas. Southern California may see rapid population growth with insect pests and severe pest pressures on garden and landscape plants after warmer weather arrives.
  4.  Monitor recent transplants regularly, at least every 2 to 3 days during cool-to-warm weather to catch wilting, irrigation, pest, disease, weed, and other problems early.
  5. Maintain or add mulch. Be cautious with adding mulch before seedlings emerge. Use fine and medium mulch such as straw, pine needles, yard clippings, and coffee grounds in new spring beds. Keep wood-chip mulch at least 30 feet from wooden buildings whenever possible to minimize the chance of termites moving from mulch to buildings.
    Mulch

    Mulch

     

  6. Harvest vegetable thinnings, last winter crops, and earliest spring crops. Cut early spring flowers for harvest.
  7. Irrigate variably depending upon rain frequency and volume; turn off irrigation during rainy periods. Provide consistent soil moisture. With the significant volume of rain in Southern California from February and March of 2019, irrigation of smaller trees and established perennials might not be needed for at least several weeks. With water held in soil, larger trees may need no further watering until early summer to midsummer or later.
    Drip irrigation

    Drip irrigation waters deeply

     

  8. Provide  shade during early heat waves; see GardenZeus Tips for Shading Vegetables During Hot Weather for creative ideas for providing shade.
    shading plants

    shading plants

     

  9. Apply organic nitrogen as plants show new growth. Add organic nitrogen such as manures as dormant fruit trees begin breaking bud, and as annuals and perennials show new winter/spring grown or once established as seedlings. Avoid fertilizing dormant trees, perennials, and new seedlings.
  10. Finish last pruning for dormant fruit trees and roses. Prune citrus anytime from winter through early summer when trees are not flowering or bearing fruit and when weather is cool to warm.

GardenZeus has customized gardening information by plant and zip code. To get started, enter your zip code here.

Other articles of interest:

Maintaining Citrus Trees in the Spring: Six Tips

Spring Maintenance: Roses, Lavender, and Bearded Iris

Heavy Feeders and Spring Planting

Starting Vegetable Seeds: A Concise Guide

GardenZeus receives commissions for purchases made through links in this post. There is no additional cost to you.

by Ann Clary and C. Darren Butler

Why start your own seeds?

Better selection. Availability of seedlings may be painfully limited at local garden centers, and they don’t always stock the best varieties for your area or the particular variety that suits your needs. Many new varieties, heirlooms, and disease-resistant varieties, such as mildew-resistant zucchini, that might produce well or offer other benefits in your garden must be started from seeds.

Healthier Plants. When started from seeds, plants adapt to your soil and current environmental conditions such as temperature, sunlight, and soil moisture. Purchased transplants may be root-bound when still small, and never produce well.

Avoid Chemicals. Start your own seeds and you can be sure that your vegetable plants are never treated with pesticides or chemical fertilizers.

Cheaper. Starting from seeds is usually the the most economical option for any vegetable. This may vary based on many factors as compared to purchasing starts from your local garden center. Do you already have seed starting materials? Are you starting many seeds for a large crop or do you just need 1 or 2 plants?

Learning and fun. See new life emerge from the soil as seeds germinate, watch starts grow under your care, and learn from what works and what doesn’t.

Remember—some vegetable plants dislike root disturbance and don’t transplant well; they should be planted directly in the soil, not transplanted from seed containers. Root vegetables, such as carrots and beets, many cucurbits such as squash and melons, and legumes such as peas and beans among others typically are not good candidates for transplanting and should be seeded directly into prepared soil.

Timing

Starting vegetable seeds at the right time of year in Southern California is important for optimal plant health, and abundant harvest. Plant too early and some vegetables may suffer in cold late-winter or spring weather. Plant too late, and the plant may not mature or produce a harvest before the heat of summer arrives.

To start seeds you’re a going to need a few—but not many—supplies.

Seeds

GardenZeus recommends open-pollinated, untreated, organically grown seeds. For additional information on choosing seeds for your area, see How to Choose the Best Seeds for California Gardens and Common Terms for Seeds and What They Mean.

Containers

Seed starting containers range from repurposed home items to specialized seed trays.

Repurposed home items save money but may be awkward or less than ideal for seed starting. Plastic containers and milk cartons aren’t biodegradable and might no longer be recyclable once modified for seed starting. Homemade paper and cardboard containers tend to fall apart from moisture. Eggshells and egg cartons may also break or fall apart, and soil may dry out quickly in any small seed-starting container. Small clay flower pots are awkward or inefficient for starting large quantities of seeds, although they can be a solution when starting a small number of seeds.

GardenZeus does not recommend either peat pots or peat pellets often sold at garden centers. Plant roots do not necessarily penetrate the bottoms of peat pots and the individual containers dry out quickly. Peat pellets are expensive and cannot be reused. And most importantly, harvest of peat moss causes environmental damage to wetlands, reduces capture of carbon from the atmosphere, and accelerates climate change.

Six-pack seedling containers are an inexpensive option. GardenZeus recommends cells that are at least 2 inches deep for sufficient root space and better moisture retention.

Flats are preferred by many gardeners for organizing and managing six-pack cells, especially indoors or anywhere water can’t drain freely, and are reusable almost indefinitely.

Seed Starting Mediums

Seed-starting mediums are NOT the same as healthy soil.  Seed-starting mediums do not have to be fertile or rich in nutrients, but they do need to be loose enough to work with easily and allow for aeration (air flow between the soil particles). Ideal seed-starting soil will retain moisture but not get waterlogged.

Gardeners can use formulas or purchase commercial potting soil mix. GardenZeus recommends a mix of 1/3 washed sand, 1/3 compost, and 1/3 soil from your garden. If soil-borne disease or insect pests have been a problem, sterilize garden soil by baking in an oven for 20 to 30 minutes at 200 degrees before adding sand and compost. Sterilizing soil also kills weed seeds—and kills the microbial life that is so important to plant health and vigor. Experienced seed-starters often formulate their own mix using combinations of any of the following: horticultural vermiculite, perlite and filtered garden soil or sifted compost. Many gardeners prefer to avoid using perlite or vermiculite in their seed-starting mixes; both vermiculite and perlite require significant energy to produce. In addition, other products, such as coir or recycled paper fiber, are perceived as from reusable or renewable resources.  Commercial seed-starting mixes may be convenient or preferred by many gardeners.

Regardless of using a homemade formula or commercial mix, GardenZeus recommends that gardeners avoid using peat moss (see “Containers” above).

Preparing Seeds

Keep in mind that some seeds benefit from presoaking while others may benefit from presprouting. See specific plant information for more details.

Planting

GardenZeus recommends moistening or presoaking the seed starting soil or medium before planting. If planting in flats or directly outdoors, place the individual seeds according to the recommended spacing for each plant. Many gardeners prefer to plant several seeds per compartment in six packs and thin to the single strongest seedling. A reasonable rule of thumb is to cover seeds to a depth of 2 to 3 times their diameter or width (the smaller dimension when a seed is placed on a flat surface). If planted too deep, seedlings might be slow to emerge or have difficulty growing to the surface. If planted too shallow, seeds may be prone to drying out or produce an exposed or weaker root system.

After planting GardenZeus recommends covering seeds with sand, light potting soil, or seed-starting medium and misting or watering.

To optimize seed germination, provide sufficient and consistent moisture and proper temperature.

Temperature

Most vegetable seeds germinate well in warm indoor areas at about 70 to 85 degrees. Some seeds need limited or specific soil temperature for best germination. Bottom heat can work wonders for improved germination. Many gardeners use heated seed-starting mats below their trays. Remember, it’s the soil temperature that matters, not air temperature.

Moisture

Keep the planting medium moist but not wet. Depending on size and age of seedlings, texture of the soil or planting medium, humidity, and temperature, this may require misting or watering as many as several times per day. Some commercial seed starting systems use a cover to increase humidity, retain moisture, and reduce watering frequency.

Other commercial products contain a continuous self-watering system to ensure that the seeds receive continuous moisture.

Grow lights can help to provide the abundant light indoors that seedlings need, especially when seedlings will be grown for days or weeks before transplanting. Grow lights have little or no effect on germination, but they can be help to support healthy and vigorous growth after seedlings emerge.

GardenZeus has customized growing information by plant and zip code. To get started, enter your zip code here.

Early Spring Planting: 3 Ideal Vegetables

Heavy Feeders and Spring Planting

Spring Gardening: 5 Tasks You Shouldn’t Forget

 

Warm Season Vegetables: Can They Be Transplanted?

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Some warm season vegetable plants are sensitive to root disturbance; gardeners should plant these vegetables directly outdoors after weather warms in the spring. Other warm season vegetables make excellent candidates for seeding into small pots or containers for later transplanting.

Solanums. Solanums, including tomatoes, peppers and eggplants are not sensitive to root disturbance and are ideal candidates for transplant. Gardeners may place seeds for tomatoes, peppers and eggplants  directly into small pots for later transplanting. Of course, seeds can also be started directly outdoors when risk of frost is low and daytime spring temperature are sufficiently warm. Different vegetables have different cultural requirements, including daytime temperatures. For more complete cultural requirements of different solanums, see tomato, pepper, hot and pepper, sweet.

Cucurbits. Unlike solanums, most cucurbits, including summer squash (including zucchini), winter squash, cucumbers and melons are sensitive to any root disturbance, such as from transplanting. Surface cultivation, digging, harvesting root crops, thinning, or weeding near established plants may also cause root disturbance to cucurbits. From the time of germination onward, it’s generally best to avoid all root disturbance as much as possible for all cucurbits. Seed cucurbits directly outdoors, when daytime temperatures are sufficiently warm. For more complete cultural requirements of different cucurbits, see summer squash, winter squash, zucchini, pumpkin and cucumber.

Corn and Beans. Like cucurbits, corn and beans, both pole and bush, are sensitive to root disturbance, including from transplanting. Again, like cucurbits, seed corn and beans directly outdoors, when daytime temperatures are sufficiently warm. For more complete cultural requirements, see corn, bean, pole and bean, bush.

Early Spring Planting: 3 Ideal Vegetables

Heavy Feeders and Spring Planting

Spring Gardening: 5 Tasks You Shouldn’t Forget

GardenZeus has comprehensive, customized growing information by plant and zip code. To get started, enter your zip code here.

Planning Vegetable Gardens in Mediterranean Climates: 3 Common Mistakes

Planning a spring garden

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This time of year, many gardeners in California’s coastal and inland valley areas, commonly described as Mediterranean climates due to their moderate, wet winters and warm, dry summers, are in the process of planning their vegetables gardens for spring and summer.  Here are three common mistakes:

Choosing the wrong plants. Pictures in national gardening media can be enticing, but plants that require extended periods of moist soil and moderate, humid temperatures (tropical plants) are generally not a good choice for gardeners who live in California or other Mediterranean climates. So no matter how much you may want to grow your own ginger or turmeric or peanuts, most California gardeners are going to struggle with these plants and reap a limited harvest. Gardeners who want to make the extra effort may be successful growing some of these plants in  containers, where specific micro climates can be carefully controlled and modified.  See Ginger: Growing and Harvesting for Culinary Use and Turmeric: Container Gardening and Harvesting. Gardeners who live in Mediterranean climates can successfully grow many of the jewels of the home herb and vegetable garden, such as tomato, corn, lettuce, basil and pumpkin. Why not choose one or more of them?

tomato

Tomato ready for harvest.

 

Choosing the wrong varieties. Keep in mind that even for the same plant, there are typically many varieties with an array of characteristics. Gardeners who live in inland valleys will generally want to select heat-tolerant varieties that will last well into the summer; gardeners along the coast will typically want to grow “early” varieties that don’t require as much heat to fruit and ripen. And each area will have a slightly different palate of pests and diseases. For example, gardeners along the coast are typically more concerned with mildews and purchasing mildew resistant varieties can be critical to success. Seed catalogs and packaging labels in garden centers typically describe a particular variety’s resistance to specific diseases. For a complete guide see Common Terms for Seeds and What They Mean. 

Planting too early or too late. Plant too early and small plants may struggle in cool, wet weather. Plant too late, and plants may not have time to develop root systems necessary to pull enough water from the soil on hot summer days or develop leaf canopies large enough to protect ripening fruit from summer sun.

Planting too late can results in stress.

Planting too late can results in stress.

 

Gardeners in most of the United States plant spring seeds based on their USDA zone. However, USDA zones are inadequate for making informed decisions about what to grow in California because they are based on average annual minimum winter temperatures only, and do not take into consideration other critical factors for California gardening and landscaping, such as summer and winter high temperatures, annual rainfall, humidity, overall climate and seasonal changes in climate, or the number of days annually of hot weather or frost. The USDA zones place portions of Los Angeles in the same zone as San Francisco, despite the vastly different growing conditions, temperature ranges, climates, and high temperatures between those two cities. Much of California’s coastal inland and valley areas are frost free, so using minimum winter temperatures and USDA zones are generally not helpful. For this reason, GardenZeus uses a climate zone system optimized for California and for your individual zip code. To take complete advantage of GardenZeus resources for California gardening, go to GardenZeus, enter your zip code and select plants. For a complete explanation of GardenZeus climate zones, go to California Climate Zones.

And remember: heirloom and open-pollinated varieties typically have a longer time to maturity than many hybrids and need to be planted before many hybrids and “early” varieties of the same plant. Seeds catalogs usually list number of days to first harvest or maturity, sometimes listed as just a number (70 days), usually meaning the average number of days from the time the seed sprouts or the seedling emerges from the ground to the time fruit or flowers can be harvested. If you are planting in new or infertile soil, are new to gardening or inexperienced with the vegetable that you are planting, or working under challenging gardening conditions, the actual time to maturity may be longer than listed in seed descriptions, and in some cases much longer. To arrive at the total number of days from planting the seed to maturity, you need to add the germination time, which varies widely for different vegetables and flowers but is most commonly about a week or two. For more information, see How to Choose the Best Seeds for California Gardeners.

GardenZeus has comprehensive, customized growing information by plant and zip code. To get started, enter your zip code here.

 

New Year’s Resolution: Grow California Native and Mediterranean Plants

by Ann Clary and C. Darren Butler

GardenZeus receives commissions for purchases made through links in this post. There is no additional cost to you.

New Year’s Resolution 4: Grow California Native and Mediterranean Plants.

Will plants sold at local gardening centers and nurseries thrive in your garden or landscape? Often they will, but in some cases, climatically inappropriate plants are sold locally. For other plants, the unique conditions in your landscape might be problematic for a plant that will thrive at another location in your neighborhood or city.

This question is even more important when purchasing online or by mail. Many to most ornamentals, fruit trees, berries, and other perennials purchased from outside of California may fail to thrive, bloom, or produce a harvest in our Mediterranean-climate areas.

Native plants from California and other Mediterranean-climate areas can provide a solution. They are adapted to survive and thrive in the many unique climates and micro-climates in California. We often tend to associate California natives with a limited range of drought-tolerant species that are commonly used in home landscapes, many of which are suited to mild, wet winters and warm-to-hot dry summers. However, it’s important to remember that California has thousands of native plant species, including many natives that need frequent watering, high or low elevations, or other specific environmental or climate conditions. Considering California natives narrows your choices to plants that are known to thrive California, but you still need to confirm suitability of native or California-friendly plant species for the location and micro-climate where they will be planted.

California natives offer many advantages to the gardener. Here are a few:

1. Use less water. California and Mediterranean natives are often drought-tolerant, and may need little or no watering once established. Many native species have special adaptations or mechanisms that allow them to survive hot and dry summers, such as going dormant. How much would you save on your water bill if you eliminate all or almost all irrigation for landscape ornamentals?

2. Minimize the use of fertilizers and soil amendments. Many California natives thrive in the moderately alkaline, poor-to-moderately-fertile soils that are common in California. They may be harmed or killed in fertile, microbially active soils with high levels of organic matter that are needed for food gardening and growing many non-native ornamentals. Soils in California’s low-rainfall areas tend to be naturally low in organic matter and may never become loamy or highly fertile without human intervention. Imagine it! California native plants generally do well in the soils here, and they usually don’t need the endless bags of amendments, applications of compost, and other amendments and fertilizers.

Hummingbird Sage

Hummingbird Sage

3. Reduce pests and diseases. Reduce use of pesticides and chemicals. When grown appropriately and not overwatered or over-fertilized, California native plants often have fewer problems with pests and diseases than non-native ornamentals, and may be easily harmed by pesticides and other chemicals. Native plants and landscapes often tolerate or need few-to-no applications of pesticides and chemicals. 

4. Less maintenance. When native species are chosen carefully and are well-suited to their growing environments, many require minimal input from gardeners as compared with non-native ornamentals. Natives accommodate your busy lifestyle by not needing as much from you, and allow you to spend time relaxing or enjoying the beauty of your garden.

Why struggle with holly when you can grow Toyon easily?

Why struggle with holly when you can grow Toyon easily?

5. Ecosystem and biodiversity benefits. Native plants feed and provide habitat for native birds, animals, and insects, including pollinators. Some native shrub and tree species potentially provide benefits to dozens or hundreds of bird and insect species. Home gardeners can help maintain biodiversity in California and provide other ecosystem benefits by growing natives at home.

 

A bee on Ceanothus.

A bee on Ceanothus.

GardenZeus has customized gardening information by plant and zip code. To get started, enter your zip code here.

 

10 January Tasks for Mediterranean Gardeners

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Many might think of January as a slow month in the Mediterranean garden, as even in mild Mediterranean climates, January often brings cool, rainy weather. Yet there is much to do in January to prepare plants for their burst of growth when the weather warms in the spring. For a customized list of gardening tasks by plant and month, find your GardenZeus Climate Zone. 

Here are 10 tasks all gardeners in Mediterranean climates should have on their January to-do lists:

  • Monitor plants regularly, at least every 2 to 5 days during cool-to-cold weather to catch wilting, irrigation, pest, disease, weed, and other problems early.
  • Plant bare-root roses, fruit trees, vines and berries.
  • Prune roses and deciduous fruit trees.
  • Protect plants from possible frost: water thoroughly and protect plants with fabric, cardboard, paper, or plastic sheets during periods of overnight frost.
  • Maintain or add mulch to garden beds.
  • Harvest citrus trees and winter vegetable crops.
  • Irrigate variably depending upon rain frequency and volume; turn off irrigation during rainy periods.
  • Add appropriate amendments and/or organic fertilizers for actively growing and/or blooming plants. Avoid fertilizing dormant plants and trees.
  • Order seeds for spring annuals and spring and summer vegetables.
  • Start seeds indoors for later transplant outdoors, such as tomatoes, lettuce, and chard.

GardenZeus recommends seeds from Botanical Interests:

Other articles of interest:

New Year’s Resolution: Focus on Soil, Not Plants

New Year’s Resolution: Compost More Waste

New Year’s Resolution: Water Plants and Trees Deeply

Rain! Rain! Rain! But is it Enough to Water Plants?

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