GardenLine | Vegetables | Vegetable Harvest Hints

The most anticipated moment for summer gardeners is harvesting the fruits of their labours. Most gardeners in their eager anticipation to feast harvest too early, or too late. The goal should be to harvest vegetables when quality is highest. After all, it is the quality of garden produce that sets it apart from store bought produce. Many vegetables not picked at the optimum time are stringy, woody, and tasteless, nullifying all the hard work and expense of growing the crop.

Here are a few guidelines to ensure that vegetables are harvested at the peak of perfection.

Beans: Green beans are ready to pick if the pods are smooth and evenly green. Snap beans are best if they snap easily when bent in half. Once snap bean pods start to turn yellow and the beans begin to corrugate, the pod the beans will be tough. Yellow bean cultivars should also be picked before they appear corrugated.

Beets: Beets may be harvested as soon as the root reaches 2.5 cm in diameter. Beets are their best at 5 cm in diameter, but over 7.5 cm they are tough and only suited to soups and processing. Only use the tender inner leaves for pot greens as the outer leaves are tough and stringy.

Broccoli: Cut broccoli when the individual flower buds are still in tight clusters. Once flower buds open, the broccoli has a strong undesirable flavour. The first harvest should consist of the central head and 12 cm of stem. A second crop can be harvested for several more weeks, but it will consist of side shoots and 12-16 cm of stem. Pick broccoli every 3-4 days so the crop does not get out of hand. Surplus broccoli can be frozen after blanching.

Brussels sprouts: Start picking the lower sprouts at 2.5-4 cm in size. The sprouts should be bright green and firm. If the weather stays cool, there many be upwards of 100 of the tiny cabbages per plant.

Cabbage: Begin harvesting cabbage head when they are small 10 cm in diameter and continue until head size reaches 15-25 cm. The heads should be firm at harvest. Waiting too late to harvest may result in split heads. Maturity may take 2-3 months, depending on the weather.

Carrots: Tiny sweet carrots can be harvested at 7.5-10 cm in length. Allow the remainder can be allowed to grow to about 2.5 cm in diameter. If carrots are allowed to reach 4 cm in diameter, they will be woody.

Cauliflower: For the best flavour, the head segments should be tightly packed, white or ivory in colour free of brown spots. When cauliflower heads start to form, leaves should be tied together at the top to form a teepee. This keeps the sun out and prevents the head from yellowing.

Corn: Harvesting corn at the right time is vital to the best flavour. Of all the vegetables, corn is most often harvested too late. The first thing to watch for is pollination which is indicated by clouds of pollen erupting when you walk through the corn patch. About 3 weeks later, the silk will turn brown. Maturity can be tested by peeling the husks back. Pop a kernel 5 cm from the tip the ear with a fingernail. If the fluid is watery, it is still too early pick; if the fluid is milky, the corn is at it best; if the fluid is the consistency of toothpaste the corn has gone starchy is only suited for creamed corn or used in chowders. The milky kernel stage only lasts for a few days.

After picking, cool corn cobs as quickly as possible, by plunging the ears into ice water and store in the refrigerator. Once cobs are picked, they immediately start turning sugars into starches, especially in warm temperatures.

Cucumbers: Cucumbers should be picked when green and about 7.5 cm long for sweet pickles, 15 cm for dills and 20 cm for slicing. Pick 4-5 times a week to encourage continuous production. Do not leave mature fruit on the vine. Once cucumbers turn yellow, a tough skin and tough seeds are formed.

Garlic/leeks/onions: Harvest green onions when the stem is a thick as a pencil. Leeks are harvested when the stem is 2-4 cm in diameter. Garlic is ready to be pulled when 1/3 of the top has died back.

Other onion types may be gathered as needed or when tops start to bend over and yellow. If onions are still actively growing by the beginning of September, bend the tops over to start a bulb curing process. A heavy frost will ruin onion bulbs. If onions do not are not curing on their own or if conditions are unfavourable for outdoor drying, spread bulbs out on the floor in a warm dry building with a forced flow of warm air. Garlic requires a curing period of about 20 days at 20°C (or 10-14 days at 27°C) with lots of air movement.

Lettuce: The outer leaves should be harvested before yellowing or browning occurs. If the stand is dense, entire plants may be harvested, giving the remaining plants more room to develop. Head lettuce should be picked firm. As semi-heading lettuce types do not form a firm centre, harvest as soon as a soft head forms.

Peas: Harvest bright green pods just before they round in cross section. Chinese and snow peas are picked when pods are still flat and about 4 - 6.5 cm long. Pods longer than 7 cm are too fibrous. Pick carefully so as not to break the vines. Do not leave overripe pods on the plants.

Bell peppers: Peppers may be harvested with a sharp knife when the fruit is dark green, regardless of size.

Potatoes: New potatoes may be dug up when the flowers form on the plant. Wait until the top growth starts to die back for fully grown tubers. If you want to store the tubers for a prolonged period of time it's advisable to wait until the crop matures. Mature tubers have a firm hard skin and are less susceptible to injuries and store well. It is best to harvest before the first killing frost. If the growing season is too short to mature the tubers naturally, the top of the plant may be killed to aid maturation. The skin will harden sufficiently if tubers are left 10-14 days in the soil.

Pumpkins: Wait until the fruit is a deep orange. The easiest method to determine ripens is to sink a fingernail into the rind. If the fingernail easily penetrates, the pumpkin is ripe enough for storage. By this time, the vines will usually be drying. If the pumpkin is not mature, leave it on the vine until after a light frost. However, if average daily temperatures are below 15°C growth is reduced or eliminated. If a heavy frost threatens, harvest and place the pumpkin in room temperature for a few weeks to harden the rind. Pumpkins may be stored at 10°C with 70 to 75 percent relative humidity.

Radishes: Thinning and eating may start when radishes are the size of marbles. Radishes may harvested up to 2.5 cm in diameter. Beyond that size radishes are pithy and strongly flavoured.

Squash/zucchini: Most people allow zucchini to become much too large. Harvest the common green zucchini when the fruit is only 15-25 cm in length. Yellow squash types should be harvested at 10-17 cm and patty pan (scallop types) when only 7-12 cm in diameter. Summer squash that grows too large has a hard skin and large inedible seeds. Spaghetti squash is harvested when a golden yellow colour and banana squash is picked when golden orange. Leave a few centimetres of stem when harvesting winter squash in late summer or fall. Winter squash skins should be hard enough to resist your fingernail. Frequent picking will encourage continuous production.

Tomatoes: For the most flavourful tomatoes, wait until they vine ripen to a uniform red colour. The full red colour develops 5 days after the first signs of pink show on the fruit. If frost is approaching and there is still green fruit on the plant, pick the tomatoes with 5 cm of stem attached or pull the entire plant. Store in a cool dark place, such as inside a brown paper bag and allow to ripen.

© 1995 Russell Friesen

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Sustainable horticultural information, offered free of charge to the public with the support of the University of Saskatchewan Extension Division, the Department of Plant Sciences and the Provincial Government.