How to Grow and Care for Black Forest Zucchini

Many zucchini plants require a great deal of garden space for their large, spreading vines. But people with small gardens, or even just patios or rooftops, can enjoy growing their own zucchinis thanks to the Black Forest zucchini (Cucurbita pepo 'Black Forest') cultivar. This is a climbing zucchini plant with yellow flowers in the summer that give way to smooth-skinned, cylindrical, dark green fruits that stretch around 6 to 8 inches long. The zucchinis’ flavor is mild and comparable to most typical bush zucchini varieties.

Unlike most zucchini varieties, Black Forest doesn’t bush out at its base. So it can be contained in a fairly large pot and trained to grow up a trellis or stake. It’s planted in the spring after the threat of frost has passed and grows quickly, reaching maturity in around 50 to 60 days.

How to Plant Black Forest Zucchini

When to Plant

Plant Black Forest zucchini seeds outdoors after your area's last frost date in the spring. You also can start seeds roughly three to four weeks prior to your area's last projected frost date if you want an earlier harvest. The plants typically do best if you wait for the soil to warm a bit, so don't rush to planting in the early spring.

Selecting a Planting Site

Pick a spot that gets lots of light and has well-draining soil. Also, the location should be sheltered from strong winds, which can damage the vines. Container growth is a good option because it allows you to control both the soil quality and environment of the plant.

Spacing, Depth, and Support

Seeds should be planted about an inch deep. And make sure to have a least a foot of space between plants. Also, provide this climbing plant with some sort of support structure, such as a stake, trellis, or fence.

Black Forest Zucchini Plant Care

Light

Black Forest zucchini needs full sun to grow and fruit at its best. Too much shade will hinder flowing (and subsequent fruiting).

Soil

This plant prefers a rich, loamy or sandy, well-draining soil with a slightly acidic to neutral soil pH.

Water

Aim for consistently moist but not soggy soil. A layer of mulch can help to retain soil moisture. Insufficient or inconsistent watering can lead to misshapen fruit. Water from the base of the plant, rather than overhead, to help prevent damp foliage that can contribute to fungal growth.

Temperature and Humidity

Mild temperatures are best for zucchini plants. Frost can kill the plants, and high temperatures can cause them to struggle, especially if they don’t get enough water. Humidity typically is not an issue as long as there’s enough air flow around the plants and their soil moisture needs are being met.

Fertilizer

This plant thrives in fertile soil. Amend the soil with compost before planting. Then, apply an organic fertilizer for fruits and vegetables when the flowers first appear in the summer.

Pollination

Each plant produces both male and female flowers. Bees and other insects help to pollinate the Black Forest zucchini. 

Black Forest Zucchini vs. Bush Zucchini

Black Forest zucchini and bush zucchini are varieties of the same species. They have similar growing needs, and their fruits don’t have a great deal of variation. However, their main difference is Black Forest zucchini produces climbing vines while the bush varieties have a shrub-like growth habit. 

Harvesting Black Forest Zucchini

The fruits will begin to appear in the summertime and continue into fall. Cut your zucchinis off the vine with a sharp knife once they reach 6 to 8 inches. If you wait too long, they can become tasteless and potentially bitter. On the flip side, you can harvest before they reach their mature size if you don’t mind smaller zucchinis. As long as you keep picking the fruits, your plant should continue to produce until temperatures get too cold in the fall, though it likely will gradually slow down before then.

How to Grow Black Forest Zucchini in Pots

Growing Black Forest zucchini in a pot keeps this climbing plant contained and makes use of your vertical garden space. It’s a perfect option for those who wish to grow their plant on a patio rather than in the garden. 

Opt for a container that’s at least 2 feet wide and deep to give your plant plenty of space. Make sure it has ample drainage holes. An unglazed clay container is ideal because it will allow excess soil moisture to evaporate through its walls. 

Pruning

This plant generally won't need pruning unless any portions become damaged or diseased. But be sure to remove fruits as they mature. Zucchinis that are left on the plant too long will begin to rot and cause the plant to cease production.

Propagating Black Forest Zucchini

It’s possible to save seeds from your zucchini plants at the end of the growing season for next year’s crop. Not only will this save you money on new plants, but it also will allow you to continue a line of plants that produced well or tasted good. Here’s how to collect the seeds:

1. Let the fruit fully ripen on the vine. 
2. Cut the fruit off the vine, and let it cure in a cool, dry spot for around three weeks.
3. Cut open the zucchini to reveal the seeds. Scoop out the seeds, and wash them in a strainer to separate them from the pulp.
4. Pat the seeds dry with a towel, and then place them on a screen to fully dry for a few days in a well-ventilated spot. 
5. Finally, store the seeds in an airtight container until the next spring.

How to Grow Black Forest Zucchini From Seed

You can start seeds either in their ultimate garden spot or in small 3-inch pots for transplanting. Select biodegradable pots, so you don’t have to disturb the seedlings’ roots. Plant the seeds about an inch deep, and water to keep the soil moist but not soggy. Keep the pots in a warm spot, roughly 68 to 77 degrees Fahrenheit. Germination should occur in about a week. 

Common Pests and Plant Diseases

Black Forest zucchini can be impacted by a some common pests, including squash bugs and squash vine borers. Wilted foliage can be a sign of these pests, but row covers can help to deter them. On the disease side, powdery mildew and blossom-end rot can afflict the Black Forest zucchini. Maintaining proper growing conditions is an ideal defense against these diseases.