Harvest Tips for Cool Season Crops

Harvest Tips for Cool Season Crops
by Botanical Interests seeds


It is officially autumn and the warm weather of summer has been replaced by cool autumn breezes in many parts of the country. Below you will find tips for harvesting cool season crops listed in alphabetical order.

Artichoke - Typical yields are 2 to 3 artichokes per plant. For eating, harvest buds when they are still closed, just before they begin to open. (Opened heads are tough.) Cut the central bud first by cutting the stem with a sharp knife 2" below the bud. After harvesting, side shoots will produce smaller harvestable buds (a unique delicacy!) if you cut the main stems to about 1 foot above the ground. Artichokes are best eaten fresh immediately after harvest as flavor declines the moment they are cut.

Arugula - Harvest leaves when no longer than 6", but at least 2" long. Pick leaves individually or cut off at ground level. Pick before plant begins to flower. If plant is allowed to flower, the foliage turns bitter, but the flowers are still edible and make a pretty garnish for salads and other dishes.

Beets - For early spring plantings, harvest before summer heat. For late summer plantings, harvest before the first heavy frost in fall. For winter plantings in frost-free climates, harvest by March. Harvest when roots are 2"-5" in diameter. Do not let them get too big; the smaller they are, the more tender they are. Foliage can be harvested when 6" tall or shorter. Leave 2" of foliage above ground level to allow re-growth.

Bok Choy White Stem - Harvest heads after 8 weeks or when the yellow flowers emerge from the center. You can also harvest outer leaves much before that (leave enough leaves to keep the plant growing). Bok Choy can also be harvested when it is quite young - baby Bok Choy is a gourmet delight when cooked whole or halved. The center stalks are called the hearts and are considered a delicacy.

Bok Choy Tatsoi - Tatsoi can be harvested at almost any stage. Generally, smaller leaves are harvested (cut at the base of the stem) for use in salad mixes, and the larger leaves and stems are harvested (cut at base of stem near the soil surface) for use in stir-fries. Young seedlings can also be used in salads. Flowering shoots can be used in stir-fry dishes. Since the plant hugs the ground, make sure to wash harvested plant parts carefully; it is easy for chunks of dirt to splash up into the plant.

Broccoli - Cut main head when 3"-6" across, buds are still tightly closed and don't show any yellow color. Cut the head with a couple inches of stem with a sharp knife. Smaller heads on the side shoots will develop an additional harvest. Don't forget, the whole broccoli plant is edible and nutritious. You can also eat the leaves and stems.

Broccoli Raab - Cut the budding shoots just before the flowers open. Additional, smaller stems will appear shortly; continue to harvest until shoots are too small and tough.

Brussels Sprouts - Brussels sprouts mature from the bottom of the plant to the top. Buds should be picked when they are firm and about the size of a large cherry, between ¾" and 1" in size. Break off the leaf just below and snap or cut off the sprout. The sprouts can be harvested all at once or in several pickings. After harvesting the lower sprouts, new smaller sprouts may emerge. To hasten harvest, cut off the top shoot when the lower sprouts are near harvestable size. But, do not do this if you want to leave the plant standing through frost or snow as the upper leaves provide protection. They can be left in the garden through a few frosts which actually improves the flavor, but be sure to harvest before the sprouts get too large and open or crack and before the foliage begins to turn yellow. To prolong harvest, mulch with straw or use row covers. Mature plants can tolerate hard frost, surviving temperatures down to 10 degrees F. The harvested sprouts will keep in the refrigerator for up to a week or the entire plant may be stored in a root cellar for longer. The leaves of Brussels sprouts are also edible and can be steamed like spinach or added to soups.

Cabbage, Chinese - Young seedlings may be harvested as you are thinning the crop. Harvest mature heads, beginning after they are 3"-4" tall, after they firm up, and are solid but not too hard. If you cut just above the soil surface, young, tender, edible leaves may then sprout from the stump. Spring crops should be harvested before seed stalks form. Fall crops should be harvested before a hard frost.

Cabbage, Common - Harvest heads as soon as they are well developed. They should feel firm and solid when squeezed. Cut off heads at the base with a sharp knife. Discard the outermost leaves. Cabbages left in the ground beyond maturity are more subject to disease and splitting. To delay harvest and prevent the heads from splitting while still in the ground, give the heads a sharp ¼ turn. This will break the feeder root, but allow smaller roots to continue to nourish the plant until harvested.

Carrots - Carrots can be harvested at almost any point in their development, but they are sweeter when mature. Check size of carrots by pushing soil away from the crown. Do not allow carrots to get larger than normal size (see vegetable description inside packet). Peak harvest period is the 3 to 4 weeks around the maturity date. Late summer planted carrots are very sweet if harvested after the first couple of light frosts. In climates where temperatures don't fall below 20 degrees F, carrots can be left in the ground for storage and harvested as needed if the plants are protected by a thick layer of mulch or a blanket. Be sure to harvest before the ground freezes. Carrots left in the ground too long will become tough and may crack. Do not pull carrots up by the leaves. Use a trowel or pitchfork to dig out of the soil. Carrot foliage is also edible and very nutritious, and can be used much like parsley in salads and other dishes.

Cauliflower - Harvest heads when buds are tight and firm. Cut the main stalk just below the head. Then, if you allow the plant to continue to grow, side shoots may occur for a second crop. The stems and leaves are also edible.

Celery - Individual outside celery stalks can be harvested at any time, allowing the inner stalks to continue to grow. Or, you can harvest the entire plant when stalks are at least 6" tall. Cut with a sharp knife at or just below soil level. Harvest should occur before the first hard frost. Celery leaves and seeds are also edible.

Endive/Escarole - Harvest when plants are 12" to 15" across. The entire head can be cut off at the base. In spring, harvest before temperatures get above 90 degrees F. Some people peel away the outer leaves, as they tend to be tougher and more bitter than inner leaves. "Greens" can actually be harvested anytime in a "cut-and-come again" fashion for the tasty, tender greens. This is particularly good when seeds are planted too late in spring and warm weather is approaching too quickly, threatening to cause plants to bolt. In fall, harvest after the first couple of light frosts; flavor is actually improved with light frost.

Kale, Chinese - Whole plants should be harvested just before the flower buds open. (In ideal conditions, the plant will be 8"-10" tall and stalks will be ¾" thick.) Or, you can pick the center bud stalks first, allowing the side branches to continue to produce flower buds for a second crop.

Kale - Young leaves can be harvested at any time and make wonderful salad greens. Pick the outer leaves periodically as the plant continues to grow. A light fall frost (28-33 degrees F) makes the leaves taste even sweeter. Continue harvesting up until the first hard frost. In mild climates, mulch plants well to continue harvesting through winter.

Kohlrabi - Harvest when round portions are 2"-3" wide. Kohlrabi gets tough and woody as plants grow larger. Kohlrabi leaves are also edible.

Leek - Leeks can be harvested at any stage, but for full-sized leeks, harvest when they are 1" in diameter. Use a garden fork to loosen the soil and then pull them up. Leeks tend to hold a lot of dirt, so rinse thoroughly. Leeks tolerate temperatures as low as 25 degrees F and can be harvested after a few light frosts. Mulch around leek plants with compost, leaves, or straw to extend the harvest into late fall (or through the winter in warm climates).

Lettuce, Butterhead - You can pick individual outer leaves before the head forms. Once the head forms, harvest the entire plant as soon as possible by cutting off the entire plant at ground level. A favorite use is to twist out the small interior head to make a lettuce "bowl" with the remaining leaf base and fill it with your favorite cold salad.

Lettuce, Crisphead - Head lettuce should be harvested in the early morning. Heads can be harvested when 4" wide and should be harvested no more than two weeks after reaching mature size of 6".

Lettuce, Leaf - Pick individual leaves anytime or shear the entire plant to 2" above the ground when plant is up to 10" in diameter. The earlier the harvest, the more tender the crop.

Lettuce, Mesclun - Mescluns can be harvested when very young for tender "baby greens" when they are 2"-3" tall. Or, they can be grown to a more mature size for heartier salad material by shearing plants to 1" above ground when plants are 4"-6" tall.

Lettuce, Romaine - Pick individual outer leaves as plant grows or shear entire plant to 2" above ground when plant is 8"-12" tall.

Mache - Harvesting can begin as tasty young seedlings. Simply cut off at ground level. Individual leaves can be picked when they are 1"-2" long. You can also wait and harvest the entire head at once if you need large quantities of leaves. Some people harvest heads when they are quite small and serve as a gourmet, baby salad.

Micro Greens - Micro greens should be harvested at a minimum when there are at least two true leaves or when the plants are 1"-2" in height. Harvest by cutting the plants just above the soil line. Rinse and use immediately.

Mustard - Harvest individual leaves from the plant as needed. Flavor is milder and texture is best when young. Entire plant may be harvested by cutting 1"-2" above soil line. New leaf growth may occur after this. If plant bolts (sends up a seed stalk), foliage becomes bitter and inedible, but the yellow flowers are an attractive addition to salads.

Onion, Bunching - These onions can be harvested any time during the growing season before they begin to bulb.

Onion, Bulbing - Grow until the tops fall over. When 50% of the tops have fallen over and are lying on the ground, knock the rest over. A week or two later when much of the foliage has dried, use a pitchfork to dig up the onions. Do not remove foliage. Dry the onions in the sun for a couple of days. When ready to use, cut off foliage, 1" above the bulb.

Parsnip - Dig roots with a shovel or garden fork, being careful not to cut or damage the roots. For best flavor, leave parsnips in the ground for at least two weeks after a hard frost in fall. Roots can be left in the ground through winter for continual harvesting if you mulch heavily with straw or compost to prevent the soil from freezing. You can also improve the sweetness by harvesting the roots in the fall and storing them at 32-34 degrees F for two weeks before using.

Peas, Shelling and Snap - Harvest when the pods are plump, about 3 weeks after flowering. Peas that are too mature will cause the plant to stop producing. Therefore, it is important to harvest daily. Use scissors to harvest or hold vine with one hand and pick pod with the other as vines are brittle. Young foliage tips and blossoms are also edible and make a lovely addition to gourmet salads.

Peas, Snow - Harvest when pods are flat, before the seeds start to form. Peas that are too mature will cause the plant to stop producing. Therefore, it is important to harvest daily. Use scissors to harvest or hold vine with one hand and pick pod wit the other as vines are brittle. Young foliage tips and blossoms are also edible and make a lovely addition to gourmet salads.

Radish, Rat Tail - Harvest pods when about the thickness of a pencil and from 3"-12" long. Harvest regularly to encourage plants to produce more pods. Mature pods become hard, tough, and bitter tasting, so they should be picked and discarded. Young radish leaves are also edible and make a spicy addition to salads.

Radish, Spring - Harvest spring radishes at any point up until they have achieved mature size (1" diameter for Cherry Belle and Easter Egg, 3"-4" long for French Breakfast, 3"-4" diameter for "Crimson Giant"). If they are allowed to grow larger or the plant bolts (sends up a seed stalk), they become pithy and hot. Young radish leaves are also edible and make a spicy addition to salads.

Radish, Summer (White Icicle) - Harvest when radish is 5" long or shorter. If they are allowed to grow larger or the plant bolts (sends up a seed stalk), they become pithy and hot. Young radish leaves are also edible and make a spicy addition to salads.

Radish, Winter - Can be harvested at any size. Harvest in late fall or early winter before the ground freezes. Sweet flavor is best when crop matures quickly. Winter radishes will hold longer in the ground than spring or summer radishes, extending the harvest period. (Mature size: Daikon - 2"-4" in diameter, 6"-20" long. Watermelon Mantang Hong - 3.25" in diameter.)

Spinach - Pick individual leaves from the outer edges as they become big enough to use or cut the whole plant 1" above the base and new leaves will grow. Harvest before the plant bolts (sends up a seed stalk).

Swiss Chard - The best quality leaves are 10" or shorter. Pick individual outer leaves as desired or harvest the entire plant by cutting it 2" above the base, and it will grow new leaves. A fairly cold tolerant annual, Swiss Chard can withstand light to moderate frost. In cold climates, mulching soil in early winter can allow harvest all the way up to late December. It can survive the winter in mild climates and will send up a seed stalk in the second year that should be removed. However, Swiss Chard tastes best in the first season, so ideally should be started fresh from seed each season.

Turnips - For the most tender roots, harvest when turnips are no larger than 2" in diameter. Greens should be harvested when young and tender. When harvesting green tops, leave 4" of foliage to continue root production.


Cool Season Vegetable Frost Tolerance

Can withstand light frost (28-33 degrees F): Artichokes, Arugula, Beets, Carrots, Cauliflower, Celery, Chinese Cabbage, Endive, Lettuce, Parsnips, Peas, Radicchio,
Swiss Chard

Can withstand hard frost (below 28 degrees F): Broccoli, Brussels Sprouts, Cabbage, Collards, Kale, Kohlrabi, Leeks, Mache, Mustard, Onions, Parsley, Peas, Radishes, Spinach, Turnips

Happy Gardening and Happy Harvesting!