Plot · field guide
How to Grow Zucchini from Seed to Harvest
Zucchini is one of the easiest crops for a new gardener, and that is the whole problem. One healthy plant makes about 8 pounds of fruit over a 5 week run, roughly 2 pounds every week. That is often more than a family can eat. Plant warm, give it room, and pick every day and you win. Plant too many and you will be leaving bags on your neighbor's porch.
Some links on this page are affiliate links. If you buy through them we may earn a small commission, at no extra cost to you. We only point to seeds and gear we would use ourselves. See our full affiliate disclosure.
Wait for warm soil to sow
Zucchini is a warm-season crop. Sow seed straight in the ground when the soil is 60 F or warmer, about a week after your last frost. Plant into cold soil and the seed rots before it sprouts.
Sow seed 1 inch deep, the depth this crop wants. Germination runs high, about 90 percent, so you do not need to plant thick. Drop two seeds per spot and pull the weaker one if both come up.
- Sow when soil hits 60 F, about a week after last frost.
- Plant seed 1 inch deep.
- About 90 percent of seed sprouts, so sow thin.
Give each plant room
Zucchini plants are big and bushy, not small. Space plants 24 inches apart in the row, with 48 inches between rows. Crowd them and airflow drops, which is how powdery mildew gets started on the leaves.
One plant needs about 4 square feet of its own. That size surprises people who picture a tidy little row. Give it the space up front so you are not fighting a mildew problem later.
- Space plants 24 inches apart in the row.
- Leave 48 inches between rows.
- Plan on about 4 square feet per plant.
One plant is often plenty
Here is the honest math. One zucchini plant makes about 8 pounds of fruit over its 5 week run, close to 2 pounds a week. For most families of four, one or two plants is all you need.
New gardeners almost always plant too many because the seedlings look small and harmless. They are not. If you want a steady supply without a flood, grow one plant, then sow a second one 4 weeks later to take over when the first slows down.
- One plant gives about 8 pounds over 5 weeks.
- That is roughly 2 pounds every week from a single plant.
- Start with one or two plants, not a whole row.
Pick every day or the plant slows
This is the rule that matters most. Pick zucchini at 6 to 8 inches long, while the skin is still glossy and thin. At the peak of the season that means checking every 1 to 2 days.
Miss a few days and you get baseball-bat zucchini with tough seeds and watery flesh. Worse, a big fruit left on the plant tells it the job is done, so it stops setting new ones. Keep picking small and the plant keeps cranking.
- Harvest at 6 to 8 inches, skin still glossy.
- Check every 1 to 2 days at peak season.
- One giant left on the vine slows all new fruit.
Watch for powdery mildew
Late in the run you will likely see a white dusty coating on the leaves. That is powdery mildew, and it is the main thing that ends a zucchini plant. It spreads fast in crowded, humid plots.
The 24 inch spacing above is your first defense because it keeps air moving. Water the soil, not the leaves, and water in the morning so leaves dry by night. Pull the worst leaves as soon as you spot the white patches to slow it down.
- Space plants 24 inches apart for airflow.
- Water the base in the morning, never the leaves at night.
- Remove the first white-coated leaves right away.
Questions, answered straight
For most families, one or two. A single plant makes about 8 pounds of fruit over 5 weeks, close to 2 pounds a week. New gardeners nearly always plant too many and end up with more than they can eat.
About 50 days from seed to first harvest. After that a healthy plant keeps producing for roughly 5 weeks as long as you pick every 1 to 2 days.
You waited too long to pick. Zucchini is best at 6 to 8 inches with glossy skin. Left a few extra days it turns into a seedy, watery giant, and a big fruit on the plant also tells it to stop making new ones.
Powdery mildew. It is the usual thing that ends the plant. Space plants 24 inches apart, water the soil in the morning instead of the leaves, and pull the first coated leaves to slow the spread.