The Plant Lady: When should you pick a peck of produce? Tips for getting the best

Jose Gilberto Anaya of Phoenix cuts organic watermelons in June 2018 at Del Bosque Farms in Firebaugh.
Jose Gilberto Anaya of Phoenix cuts organic watermelons in June 2018 at Del Bosque Farms in Firebaugh.

Growing your own summer vegetables can be very rewarding, but picking them too soon or late can be disappointing and frustrating. Some vegetables are easy to tell when ripe – such as tomatoes (soft but firm) and zucchini (monitor the size). Other vegetables are not as forgiving.

Here are a few tips and tricks to help you guide your summer harvest.

Sweet Corn

There are two key signs indicating corn is ready to pick. First, look at the tassels hanging out the ears of corn. Make sure the majority are brown. If the husks themselves are brown then you waited too long. If you are still unsure, you can peel back part of the husk and poke a kernel or two. A ripe, ready-to-be-picked cob will emit a milky sap. If it’s underripe, the sap will be clear. If it’s overripe, the sap will be starchy. Try to gauge the ripeness from the tassels first, since opening the ear exposes the cob to a risk of pests.


Potatoes can be tricky since you can’t actually see them – but there are two major times to harvest. If you prefer young, “new” potatoes, you can start harvesting when the plant is in bloom. If you want large, mature “storage” potatoes, you will have to wait a bit longer until the plant foliage is yellowing and dying. This can be anywhere from late summer into fall.

To harvest “new” potatoes, dig down into the soil carefully and pluck a few out, covering the exposed roots back up. If you know you will want a lot of “new” potatoes, it may be a good idea to designate a few plants for this purpose. Harvesting larger potatoes is easier – simply uproot the entire root mass with a spading fork.

It is best to let the potatoes sit in a cool, dry area up to two weeks so the skins harden a bit. This allows them to store better. Never let any potato sit out in the sun, though. This causes them to green up, which is an indicator they are producing more than normal amounts of a toxin called solanine (which can be dangerous if too much is consumed).


Harvesting an underripe watermelon is the worst, as they do not ripen once picked. Luckily there are a few outward signs to let you know when it’s time to harvest. First, look for the tendril closest to the watermelon. The tendril is the curly-cue appendage, which is a modified leaf that allows the vine to grow upwards. This tendril should be almost completely brown and shriveled when you harvest.

Additionally, look at the color of the watermelon on the side laying on the ground. Generally, a ripe watermelon will have a large yellowish patch – make sure it is actually yellow and not just white. Lastly, some people swear by thumping on the watermelon. The thump should make a nice hollow sound. This in conjunction with the other tips will ensure you pick at the correct time.


Cantaloupe is extremely easy to harvest – they will fall right off the stem when ready. Careful though: Once they fall off they will rot very quickly. When you think they are getting close, be sure to check often. Color is a very good indicator, as a ripe cantaloupe will change from gray/green to apricot orange. Also, the stem attaching the melon to the plant will turn brown. The nose will lead the way for you as well, as a ripe cantaloupe will smell very sweet.


Peppers can be picked at various stages without any problems. However, if you are seeking a certain taste, here are a few tips. Sweet peppers will store up more sugars the longer they are left on the plant, changing color from green to orange to red. Impatient gardeners (me) usually pick when green. Hot peppers, if left on longer, will store up more capsaicin, resulting in hotter peppers. Also, don’t yank peppers off the plant – most need to be cut off so damage to the plant does not occur.

Winter Squash

Acorn squash and butternut squash need to be hard before picking. Usually by this time the stem holding the fruit on the plant will be brown. Color is a good indicator too. The skin should be dull and even colored.


Halloween is a key date in which people want their pumpkins to be ripe. Luckily, pumpkins are forgiving – they will last long both on and off the vine. However, they will not change color once picked. If your pumpkin ripens weeks ahead of Halloween, simply leave on the vine or place in a shady cool location. You know your pumpkin is ripe when the color is shiny, the stem is brown and firm, the skin is very hard to pierce and it makes a hollow sound when thumped.


If you prefer a tangy tomatillo – think salsa – harvest when the husk splits revealing the green fruit. If you desire a sweeter fruit, then wait until the husk turns papery and the tomatillo turns yellow or purple depending on the variety.

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