It is hard to give precise advice on harvesting vegetables because there are times when flavor is the prime consideration and at other times the important factor is the vegetable’s keeping factor. As a general guide try the following.
Asparagus: If you prefer blanched spears, hill soil over the bed and when the lips appear cut down into the soil with a sharp knife. Where green spears are favored grow to 15 centimeters from ground level. Cut below the surface and always with a sharp knife.
Brussels sprouts: These are ready to use from when the size of a walnut. You’ll notice how Brussels sprouts form at the base of a leaf. Always remove this corresponding leaf when picking sprouts and choose those nearest the soil. Don’t pick the leaves that are higher up the plant as you could find that the remaining stub may not grow.
Beans: French beans are at their peak when the seed begins to enlarge in the pod. They’ll crop for a longer period if picked at this stage of development. Don’t leave beans to grow tough and useless. Remember they deep freeze well.
Broad beans are becoming increasingly popular, picked and used like French beans, before the seeds enlarge. Try cooking them in this manner occasionally. If left to mature, eat the seed portion only.
Beetroot: Try using when about a centimeter in diameter and cook both the roots and tops. Quite delicious! Mature beet tends to lose its flavor when the weather’s hot but lasts for ages in the ground in winter.
Don’t buy beet that has developed white rings inside the roots. It can be tasteless and has lost a good deal of its sugar content. Screw rather than cut off the tops of beet, so that it bleeds less and remains a better color when cooked.
Broccoli: Cut the main head to about 15 centimeters when the buds are still tightly closed. Watch the warm weather, as this is when broccoli matures quickly. Once the central head has been cut, side shoots appear. Cut these at the same stage of development.
Cabbages: When hard to the touch, cabbages are ready to pick. Grow ‘Usherette’. It remains in good condition for several weeks. ‘Green Gold’ and ‘Velocity’ should be used promptly once the heads harden.
Carrots: Remain in good condition for long periods with only minor loss of quality. If carrots are sown now they are unlikely to seed until spring.
Cauliflowers: Best cut before heads open. However, flavor does not deteriorate as quickly as is generally imagined. Don’t forget to tie the outer leaves over the head to keep the flower snowy white.
Cucumbers: Use before the fruit hardens. Pick green varieties when they are a deep green color, as they tend to become bitter as the skin yellows. Pick the fruit at least bi-weekly.
Leeks: The hearts are ready to use any time after they start to form and are at their prime when firm to touch.
Onions: Early flat white can be used at any stage, but brown varieties should be allowed to develop until the tops yellow and wilt. Pull at this stage and dry for a month. Allow plenty of air circulation when storing.
Peas: At their best when the pod is snugly filled but before it begins to crinkle. At this time the seeds are very sweet. Later sugars convert to starch and the flavor deteriorates. Don’t forget that peas continue to ripen after picking, so use quickly.
Potatoes: Can be used at almost any time. After harvesting, cover the tubers from light otherwise they turn green and are poisonous.
Pumpkins: As soon as the skin hardens the pumpkin is sufficiently mature to eat. If storing, delay picking until the vine dies down. Store at a temperature around 10 degrees Celsius and always pick fruit with a length of stalk attached.
Tomatoes: Leave on the bushes to ripen or pick at semi-ripe stage and keep in a warm place.