WARM SEASON HARVESTING TIP SHEET

INTRODUCTION

With the “warm season” upon us, we’re harvesting a greater variety of crops than we harvested during the cooler months. A basic knowledge of harvesting tips and techniques will not only improve your yield but also maximize the nutritional content in your food. How do we know when to pick those vegetable “fruits” like tomatoes, cucumbers, beans, etc,., among many other things? 

As with any gardening endeavor, a good rule of thumb is to know your plant. All vegetable crops differ, just as landscaping plants are different - some grow taller, some grow shorter, some need more water than others, etc. Some varieties of a given crop grow much larger than other varieties of the same crop. Some crops turn a certain color when ripe, others another color. Know your plant!

Minimize damage to plants by harvesting with clean sharp cuts using clippers or kitchen scissors, whenever possible. Pulling or tearing can rip stems and damage tender leaf tissue; roots and stems of young plants in particular are easily damaged when the harvest is “pulled” off the plant. Many vegetable fruits like tomatoes and melons will pop right off the plant when ripe, so you won’t need clippers for that, though it sometimes makes the job easier.

Generally, vegetable crops remain fresh in storage longer when picked early in the morning or in the evening after the sun has set. Any crop can be harvested any time of the day for immediate use. Many leafy vegetables and roots crops quickly wilt when picked during the hottest part of the day. 

Know your plant - it’s fun! To take some of the guess work out of it all, here are some of the basics for harvesting your warm season crops.

VEGETABLE “FRUITS”

Many of our most common vegetables are actually fruits, e.g. tomatoes, eggplants, cucumbers, squash, tomatillos, etc. When to harvest each depends on which crops you’re harvesting. Within a given crop, there are many different varieties that may need to be harvested at different times. For instance some tomatoes and peppers are ripe when they are red, some yellow, and some orange. Again, know your plant!

Tomatoes

Often tomatoes are picked based on color and softness. That being said, some varieties have thicker skins than others when ripe, especially when grown in pots. Tomatoes are generally softer when ripe but not necessarily, and tomatoes within a given variety vary in size quite a bit when ripe. 

Therefore, color is your best cue for when to pick tomatoes. Tomatoes can ripen in a wide variety of colors depending on the variety from the pale yellow ‘Lemon Boy’ to the bright orange ‘Sungold’ to the green/gold marbled ‘Green Zebra’, to the deep red ‘Beefsteak’ to the rich, dark red ‘Black Krim’. Know your plant! 

Here’s another way to check for tomato ripeness. Have you ever noticed that little “knuckle” in the tomato stem where it  joins the rest of the plant? If you gently pull on the tomato to flex that knuckle, a ripe tomato will pop right off. If you feel the slightest resistance, the tomato should be left on the plant.

Peppers

Like tomatoes, there are many kinds of peppers, and you’ll have to know what kind of pepper you have to really know when to harvest. For some peppers the “fruit” grows much bigger (e.g. Poblano, Bell) while some remain smaller (e.g. Padron, Serrano); some turn red, orange, yellow, purple, or even brown when fully ripe. 

Almost all green-colored peppers will change to some other color, or ripen,

if left on the plant long enough. Yes, a green bell pepper is always just an unripe bell pepper. Jalapenos, Anaheim, and Sweet Banana will turn red and often develop sweeter or more robust flavor if left on the plant.

You might then ask then, “So when I go to the store why do I see only green Jalapenos, Poblanos, Anaheim, etc. and not red ones, if red means ripe?” For many people “green” colored peppers are good enough, especially when grilled or sautéed. But the main reason peppers are picked green is the yield in numbers of peppers per plant is much higher. If the plant can’t grow ripe peppers (fruit) the plant must make more flowers to try again, which results in more peppers (fruit). This is the basic idea of “deadheading” spent flowers - to remove the potential seed pod so that the plant must put more energy into creating more flowers. 

So if all peppers were picked ripe, they would cost more because (1) they take longer to ripen and (2) the yield is lower per plant, because the plant puts more energy into seed, not needing more flowers and the subsequent peppers (fruit).

When to pick peppers is entirely up to you and your tastes. Experiment, and of course, know your plant.

Cucumbers

With cucumbers you really need to know what kind or variety you have to know when to harvest. There are many different kinds, and they all have the potential to produce a lot of cucumbers. Knowing when to pick each kind gives you optimal flavor, thinner skins and less seeds. If left on the plant too long, all cucumbers vastly decline in flavor, the skin grows thicker, and the seed grow bigger and harder.

For instance, Persian Cucumbers when picked 5-7” long will have very thin skins, few or no seeds and a nicely, sweet flavor. Japanese Cucumbers and Burpless/English Cucumbers, may grow up to two feet long before they need to be picked. The common slicing cucumbers are picked 6-9” long before the skin gets thicker and the seeds become harder. Armenian Cucumbers get huge, and are light green with long ribs. 

Lemon Cucumbers (look like lemons, taste like cucumbers) are best picked based on color. Pale yellow is what you want; if left on the plant too long, Lemon Cucumbers will turn a brownish, golden-yellow - at this point they’ll have really thick skins and lots of hard seeds. The popular Pickling Cucumbers actually make some of the best slicing cucumbers; pick them whatever size you want usually between 3-5” long.

Summer/Winter Squash & Pumpkins

All kinds off squash are best planted during the warm season from late  winter or early spring through fall, depending on the type of squash. In more protected microclimates zucchini squash, and others, can produce all winter long. 

Summer Squash and Winter Squash differ by when they are harvested. Summer Squash varieties are picked and eaten right away; Winter Squash varieties differ in that the squash/fruit stores for the winter.

Summer Squash varieties include: Green/Yellow/Italian/Mexican Zucchini, Crookneck Squash, Patty/Peter Pan/Scalloped Squash, 8 Ball Zucchini Squash. Winter Squash varieties, on the other hand, include: Acorn, Butternut, Delicata, Sweet Meat, Blue Hubbard, Spaghetti, Pink Banana among many, many others.

Summer and Winter Squash are harvested differently based on what is known as the “thumbnail test”. For Summer Squash, you can harvest if you can push you thumbnail into the skin of the squash; if your thumbnail won’t go into the squash, it’s over-ripe and not, so good. 

Winter Squash, however, should be harvested only if your thumbnail will not press into the skin of the squash. Once the skin is that hard, it will store for much longer than if the skin is still soft enough for your thumbnail to go into it. Pumpkins are actually a type of winter squash so use your thumbnail test after they turn color. 

Melons

Melons are one of those fruits that do not ripen any further once they are picked from the plant. Generally melons refers to Watermelon, Cantaloupe, Honeydew, Crenshaw, Canary, Christmas, Honeyloupe, Casaba, and many more. When melons are fully ripe the “flower end” of the fruit (i.e. the end where the flower was attached) should be slightly soft; watermelons are maybe an exception. Also, a ripe melon will typically separate easily from the vine and pop right off when gently moved. If you feel any resistance from the fruit trying to separate it from the vine, leave it for another day.

Beans

Pole beans vs. bush beans differ in their growth habit but are similar in how and when they’re harvested. Bean are picked depending on how they’re used. When picked for the edible pod Green Beans, Burgundy Bush Beans, and Yellow Wax Beans, for instance, are picked as small you want up to as large as you want, as long as the skin is still soft.

“Cooking” beans like Lima, Kidney, Black Eyes Peas, and Cow Peas are harvested once the seed pod has dried on the plant. After the seed pod has dried the beans will store for a much, much longer time than when harvested fresh.

The most important thing to remember when harvesting all beans, is to actually pick them! Being an annual, peas have basically one season to grow, create seed and die. By removing the pods (which prevents the plant from “going to seed“), the pea plants will have no choice but to continue to flower and thus make more pods. By allowing seeds to remain on the plant in unharvested pods, production greatly declines. This is mainly the same reason why commercially grown peppers are picked green.

Eggplant

Here again it is really important to know what kind of eggplant you have. Some mature when dark purple (e.g. Ichiban, Japanese Millionaire, Italian); some when light purple (e.g. Chinese eggplant like Ping Tung Long) some when white (e.g. Caspar), some when green (Kermit), some when multi-colored (e.g. Rosa Bianca). Brown tints in the skin often means the plant has been left on the plant too long.

“ROOT” CROPS

(Beet, Carrot, Radish, Parsnips, Turnip, Rutabaga, etc.)

How does one know when to harvest carrots, beets or radishes if the root is in the ground? The best way to know if your root crops are ready to harvest if to work your finger around in the top inch of soil feeling for those swollen roots. 

The nice thing is that almost all root crops tend to push themselves up out of the ground a bit as the root develops. Especially for those of you with shallower raised beds, you may see a portion of the top of the roots exposed. It is a good idea to keep covering the tops of exposed roots with compost if they push up a bit.

Radishes and carrots tend to have that basic 1” size that we are all familiar with. Beets, turnips, and rutabagas on the other hand can widely vary in size depending on the variety, spacing, and environmental conditions (water, soil, etc.). Again, the best method to know when to harvest is to poke around a bit in the ground.

Radishes are one of the quickest root crops to mature, while carrots and parsnips will take several months. Remember that the leaves of all the above mentioned roots crops can be eaten too!

ALLIUMS 

(Onions, Garlic, Shallots, Green Onions, Chives, Leeks)

“Allium” refers to the botanical name for Onions, Garlic, Shallots, Green Onion/Scallions, Chives, Garlic Chives, Leeks, etc.). Different Alliums are harvested in different ways depending on which one you have.

For Onions, Shallots, and Garlic we’re harvesting a actual “bulb“. As with the root crops described above, you can poke around with your finger to see how the bulb is growing and when to harvest. All three of these will store longer if you let them “dry out” for a few days before storing. Storing any type of bulb with wet skins can promote mold. 

With Green Onions, Chives, and Garlic Chives and Leeks, we’re typically harvesting shoots of the plant, which are often sold bundled. But did you know that Alliums are perennial crops? You can simply clip or cut them off at the base and they will regrow. You might say, “But I like the white part of the Green Onion or Leeks down in the ground.” Certainly you can go ahead and pull them up; you can also pull away some of the soil and cut the shoot off down lower to get more of the “white”. As long as the roots are intact, the plant will regrow.

PERENNIAL HERBS - persist for several years 

(Sage, thyme, rosemary, winter savory, oregano, marjoram, etc.) 

Herbs can be harvested fresh as needed or harvested and dried for future use. Common sense typically prevails here, so just clip any leaves as you need them. These perennial herbs will persist for many years. By harvesting the leaves on the branch tips, you will induce the plant to branch more, which increases your yield. The flowers on any of these herbs are edible too! Use the opportunity you have harvesting to shape your plants any way you would like. 

ANNUAL/BIENNIAL HERBS - will need to be replanted at some point

(dill, cilantro, parsley, basil, etc.)

Dill, cilantro, and parsley all have the same basic growth habit. They grow leafy shoots that eventually produce a flower at the top of the shoot (sooner in cilantro, later in parsley). Here again, clip any leaves that you need as you need them. You can either harvest the oldest leaves on each plant or cut groups of leaves a couple of inches above ground level. Regular scissors work fine; be sure they are sharp. Simply pulling on the leaves of a young cilantro plant, for instance, can uproot the entire plant.

If you see your dill or cilantro start to create a vertical flowering stem, cut that off (harvest the leaves on the stem). When you prevent the plant from flowering, it will be forced to grow more leaves.

Basil, on the other hand, grows differently from the above mentioned annual herbs in that it creates branches, more like a shrub. Here again, one can simply harvest any leaves that you need. We suggest you target two types of leaves for harvest. (1) First, harvest the largest leaves on the plant. By removing the largest leaves, usually those attached to central stems, more light reaches the interior of the plant. (2) Harvest stem tips. This promotes more branching and bushiness and prevents flowering, both of which increase yield. 

Never let your basil plant flower. Because they are annuals, once basil starts to create seed, “it’s job is over”, and plants start to decline. As soon as you see a flower bud forming at the end of a stem, nip it off; eat it too!

A few types of basil are actually perennial (e.g. African Blue basil, Greek Columnar basil, Tulsi/Holy Basil) and should be harvest like the above mentioned perennial herbs. These plants will have a better shape and a higher yield of leaves if prevented from flowering. However, there is no need to prevent flowers because the plants are perennial. African Blue Basil is one of the best bee attractors for the vegetable garden; it produces no seed and become a large shrubs; try eating the flowers!

WARM SEASON SALAD GREENS

We see the common salad greens in the store (e.g. lettuce, spinach, chard, arugula, kale, etc.) in one of two ways: (1) whole plants (e.g. heads of lettuce), or (2) packaged “baby” greens or young leaves. 

The tradeoff here is that we can let a plant “mature” and harvest a larger quantity at one time or we can regularly harvest tender, younger, more nutritionally rich leaves over a longer period of time.

We like to encourage home gardeners to harvest the second way, by removing one or two of the lowest, “baby” leaves on each plant. Harvesting this way, the plant continues to grow by creating new leaves in the center of the plant while you remove the oldest, lower leaves on the plant. “Baby Greens” typically does not refer to any particular variety of plant, but simply refers to leaves that are picked when young and small.

For lettuce, remove as much of the leaf as possible. For those leaves with “stalks” like kale, spinach, chard, and arugula, harvest the entire leaf stalk too. Harvesting the stalk also helps the leaves last longer in the refrigerator. 

Lesser common, truly heat-tolerant salad greens include many common weeds like Lamb’s Quarters, Purslane, Amaranth, as well as perennial plants like Malabar Spinach, Salad Burnet, Longevity Greens. Explore some of the “wild” salad greens, and ask your farmhand about including some of your favorites.

GET READY TO PICK!

While it is vitally important to “know your plant; you must also be ready to get out there and harvest. Don’t be afraid to pick leaves. Have part of your daily routine to go out and at least look at the plants in your garden. 

I really believe that if you at least go look at your plants every day, they’ll grow better; I can’t prove that, but I guarantee it’s true. Have fun gardening, ask questions, and know your plant!