This super-productive and high-yielding warm weather annual veggie will provide you with a delicious bounty. Summer squash plants are fast growing and usually easy to care for. They don’t spread as much as their winter squash relatives, which saves you room for more diversity in your garden. These squash grow large leaves and bright yellow flowers, which are either male or female, and require pollination by insect or hand. Both the flowers and fruits are edible. True to their name, summer squash will not tolerate frosts, but take note that they also aren’t too keen on extreme heat, either.
The Black Beauty Zucchini, also sometimes known as Courgette, produces a dark green-skinned fruit with a creamy white flesh that is best eaten when young. This variety started to appear in the US in the 1920s and has gained increasing popularity since.
Seed Depth: 1/2–1″
Space Between Plants: 24″
Space Between Rows: 3–4′
Germination Soil Temperature: 70–95°F
Days for Germination: 6–15
Sow Indoors: Not recommended. If your growing season is very short, start indoors 2–4 weeks before average last frost date using a biodegradable pot which can be planted directly into the ground.
Sow Outdoors: 2–4 weeks after average last frost date when soil temperatures are at least 60°F. As late as 12 weeks before average first frost date for fall crop.
Vegetative: Can be propagated by taking stem cuttings. Cuttings should contain between 1–3 nodes. Root your cuttings in well-drained soilless media. Plants grown from cuttings will potentially produce fruit earlier than plants grown from seed.
Grows best in warm weather and will not tolerate frosts. In fact, a light row cover is helpful to young plants if nighttime temperatures are below 65°F. For germination, soil temperature needs to be at least 60°F (over 70°F is ideal). A few weeks before planting, cover soil with black landscaping fabric or another dark material where you plan to grow summer squash in order to heat the soil. You can also start in midsummer to time the harvest for just before your average first fall frost.
Natural: Full sun.
Artificial: Grows best under HID lights, particularly an HPS lamp. Needs at least 6–8 hours of light daily; however, more is preferred.
Soil: Prefers well-drained loamy soil with a high amount of organic matter. A pH of between 6.3 and 6.5 will keep plants healthy and nourished.
Soilless: Germinate seeds in a sterile soilless mix containing coco coir, well-rotted manure, and/or perlite, or use mineral wool cubes.
Hydroponics: Thrives in a variety of hydroponic systems, including a media-based system.
Aeroponics: Can grow in a larger aeroponic system.
Water: Requires high levels of water. Aim for at least 1 inch of water per week, and always water deeply. Consistent moisture is key to growing productive plants, especially when fruits are forming. Use drip irrigation or a soaker hose to keep leaves dry, which will prevent disease.
Nutrients: Requires high levels of nutrients to support its quick growth. Amend soil with generous amounts of compost and/or aged manure before planting to provide organic matter. When the blooms begin to form, side dress with compost or a balanced organic fertilizer. Continue to fertilize 1–2 times per month throughout the growing season.
Foliar: Will benefit from a foliar feed of compost tea or liquid seaweed 1–2 times per month during the growing season.
Mulching: Use mulch to protect roots, suppress weeds, and conserve soil moisture. Black landscaping fabric placed over the planting area in late winter will heat the soil and allow you to plant seeds earlier. (We recommend folding this durable material up and reusing it next season rather than resorting to wasteful disposal each year!) Once plants have matured, their large leaves will shade the soil, so only a light mulch is needed.
Other When transplanting seedlings outside, provide them with partial shade for the first few days to prevent plants from wilting.
Deficiency(s): A nitrogen deficiency can cause misshapen fruit. A calcium deficiency or irregular water levels can cause a condition known as blossom-end rot.
Rotation: A 3-year rotation away from all plants in the cucurbit family is recommended if you have disease or pest issues.
Companions: Grows well with plants such as the Three Sisters, peas, eggplant, marigold, nasturtium, onions, and radishes. Avoid potatoes.
Harvest: Harvest should begin about 60 days after planting or a week after flowering. When fruits reach 6–10 inches in length, cut them from the plant about 1″ from their tops. Check plants daily because these fruits grow fast, and taste and texture is best when young. If you get a zucchini over 12″ in length with seeds beginning to form inside, use for cooking breads or cakes. To harvest flowers, pick them early in the day when they are still open, or you’ll risk taking a captured bee in with the flower! This will also allow them to stay fresh longer.
Storage: Carefully wash and keep fruits in the refrigerator for up to 10 days, but ideally you’ll eat or preserve it sooner. Frozen summer squash can be stored for up to 2 months. Use flowers as soon as you can, since these delicate blooms won’t last long off the plant.
Pollination: Summer squash needs to be pollinated for fruit to form, either by insects (usually bees) or by hand. Each plant bears both male and female flowers; the female ones can be differentiated by a tiny green bulb found under the base of each flower. To manually pollinate, use a paintbrush to move pollen from male flowers to the ovaries of the female flowers. Flowers are most open early in the day.
Zucchinis are made of about 95% water! This makes it the perfect veggie to snack on during long, hot summer days.
Preserve: Blanch and freeze slices or cubes of summer squash for later use. It can also be grated or pureed if you plan to use it in soup or bread recipes. You can also make delicious pickles from young zucchinis.
Prepare: The skin, flesh, seeds, and even flowers of this plant are all edible. Flowers are mostly seen served battered and fried and are quite the delicacy. The fleshy fruits are used steamed, fried, sautéed, or baked. It can even be grated and used as a gluten-free pasta substitute. If you delay your harvest and have some fully-formed seeds, these can be rinsed and roasted with salt for a healthy snack.
Nutritional: Provides vitamin(s) C, A, folate, potassium, and some manganese.
Medicinal: The antioxidants found in zucchini, particularly the skin, are beneficial in supporting health and are possible anti-cancer compounds. Regular consumption may also provide protection against diabetes.
Make this delicious sweet and spicy Vegan Zucchini Bread using your extra bounty.