Yellow Crookneck
Zucchini (Courgette) in the US

You'll want to get your zucchini started when the soil's warmed up properly. For folks in Zone 5, that's usually May. Zone 6 and 7 can start a bit earlier in April or May, and if you're in Zone 8 or 9, March or April is good. You can sow seeds indoors, about 2 to 4 weeks before your last frost, putting them an inch (2.5 cm) deep in small pots. Or, if your soil is nice and warm, direct sow them outside after all danger of frost has passed. Give them plenty of space from the off, as they get big.

Once your indoor-sown plants have a few true leaves, you'll need to harden them off before planting out. This means gradually getting them used to the outdoors over a week or two. Plant them into rich soil in full sun after your last frost, giving them a good 3 feet (90 cm) between plants if they're a bush type, even more for vining varieties. You can grow some in proper big containers too, mind.