Pumpkins grow and produce best at daytime temperatures of about 65° to 75°F, and while many varieties tolerate heat, growth and fruiting may be diminished at temperatures above 85°F. This creates a conundrum for California gardeners in hot-summer areas who want to grow pumpkins for Halloween.
With many California areas having highs above 100°F and some with highs above 115°F from July through September or October, what is the best way to time planting and cultivation of garden pumpkins such that despite seasonal heat, your homegrown pumpkins are ready for harvest or still fresh enough for carving or eating by Halloween and Thanksgiving?
GardenZeus expert Darren Butler recommends 3 possible strategies for growing homegrown pumpkins outdoors for Halloween in California hot-summer areas. These strategies also apply for growing pumpkins or winter squash for Thanksgiving decoration or cooking in hot-summer areas. Exact timing may vary depending upon seasonal temperatures in your area.
– 1) Choose Cucurbita maxima and Cucurbita pepo varieties that store well for long periods, and plant from about March through early April during cool weather, or as early in spring as possible after daytime temperatures are consistently 60°F or above in your area. Harvest by late June or July in most areas. Cure pumpkins, then store in a cool, dry, dark place until October.
– 2) Plant Cucurbita moschata varieties, which are more heat tolerant than maxima and pepo varieties, particularly Musquee de Provence, until slightly later or until late April in many areas, for harvest by July or August. Cure and store until Halloween or Thanksgiving.
– 3) For experienced and dedicated (brave and obsessed?) gardeners with fertile soil, my 3rd strategy is to take on the summer heat. Plant moschata heat-tolerant varieties only into rich, loose, deep, living soil, in late spring or even early summer, from May to June in many hot-summer areas during periods when weather is forecast to be cool. Provide shade protection and careful attention daily during hot weather, use shadecloth after daytime temperatures are consistently above 85°F, hope for a cooler-than-average summer, and harvest in September or October.
Other articles that may be of interests include: Growing Winter Squash and Pumpkin in the California Home Garden; Grow Cucurbits in a Mature Compost Pile; and Saving Pumpkin Seeds: It’s Complicated;