When Should You Harvest Courgettes and Squash?

Courgettes and squash are among the most productive crops in any kitchen garden, but they demand attention. A courgette that is finger-sized on Monday morning can be an arm-length marrow by Friday. Getting the timing right means checking the plant every single day at peak season and understanding that the rules for summer and winter squash are completely different.

Courgettes: Harvest Small for Best Flavour

The ideal courgette for eating is 15–20 cm long and firm along its full length. At this size the seeds are tiny, the flesh is dense, and the skin still has a slight sheen. Courgettes harvested at 10–12 cm — sometimes called baby courgettes or with their flower still attached — are considered a delicacy and command a premium at markets. Leave a courgette to grow past 25 cm and the flavour becomes watery, the seeds large, and the skin tough. Once it reaches marrow size, you have a different vegetable entirely. The plant reads an unharvested fruit as a signal to reduce production, so frequent picking directly increases overall yield.

How to Cut Courgettes Without Harming the Plant

Always cut, never twist. Courgettes are attached to thick, fibrous stems; twisting pulls on the plant crown and can open wounds that invite disease. Use a sharp knife or secateurs and cut the stem an inch above the fruit. The stub remaining on the plant will dry and seal cleanly. Avoid cutting during wet weather if you can — open wounds on the plant are more vulnerable to infection when conditions are humid. If your plant is sprawling and hard to navigate, move leaves gently aside rather than stepping over stems.

Summer Squash Varieties

Patty pan squash, yellow crookneck, and tromboncino are harvested the same way as courgettes — young and tender. Patty pans are best at golf-ball to tennis-ball size, when the skin is still soft enough to eat. Tromboncino can be harvested young as a courgette substitute or left to mature fully as a winter squash — in the latter case, wait until the skin is thoroughly hardened and the vine has begun to dry.

Winter Squash: A Completely Different Approach

Butternut squash, Crown Prince, Hokkaido, and other winter varieties are left on the vine until they are fully ripe. The skin should resist a fingernail press — if your nail punctures it easily, more time is needed. The stem connecting the fruit to the vine dries and turns corky; when this happens on most of the fruit, harvest time has arrived. Cut with a generous 5 cm of stem attached — this extends storage life significantly. Bring winter squash indoors before the first frost and cure in a warm room for 10–14 days to harden the skin further before storing.