How to Make your Garden Harvest Last Longer

When I first started to grow produce for sale and not just for my own use, one of the hardest parts was figuring out how to preserve what I had grown so that it would last not only through a Saturday farmers market, but maybe to the next Wednesday market as well. (Side note: it’s a myth that farmers get up and harvest hundreds of pounds of produce the morning of a farmers market – they don’t. It takes too long to process produce to do it the morning of, and then also pack it and get it to market. Most things are harvested the day before).

During my research on how to handle produce for optimum holding, I ran across a phrase that was new to me: Field Heat. Field heat is the temperature the produce is at when its picked and how active the plants metabolism is at the time of harvest. REMOVING the field heat as soon as possible after picking is critical for making produce last longer. Turns out, this is also true for your own garden vegetables.

Fresh produce is metabolically still alive. Your harvest will continue to use stored food reserves to breathe or “respirate” after being severed from its roots, but those reserves are no longer replaced by water and photosynthesis. And the warmer they are at the time of harvest and immediately afterwords, the faster that metabolic activity and the quicker your harvest will degrade.

Different plants have different respiration rates. High, very high and extremely high rate vegetables include: carrots (with tops), cauliflower, cucumber, leeks, leaf lettuce, radish (with tops), artichoke, broccoli, Brussels sprouts, green onions, kale, okra, snap beans, asparagus, peas, spinach, sweet corn, and other greens (mustard, Swiss chard, collards etc.) and beets (with tops). This means that for this produce, the cooler the temperatures when picked and the faster the field heat is removed, the better the quality and the longer these vegetables will store.

If there’s one thing I know, it’s that sometimes you harvest when you can, and that’s that. But best case scenario, harvesting during the cool of the morning is almost always better for most vegetables (there are those who will argue that tomatoes are best harvested later in the day when the sugars are more concentrated, leading to a sweeter flavor).

If you’re doing an extended harvest, stow harvested produce out of direct sun as soon as possible while you continue to pick. And then cool produce with water if needed (greens for sure, and anything in the brassica family) and transfer it to a refrigerated location as soon as possible. Pro chef tip: leafy greens will reabsorb water through their leaf stomata (aka their pores) and rehydrate. So if you have some limp lettuce or other greens, soaking them in a sink of cool water for 10-20 minutes, shaking off the excess and then putting them back in the fridge will often “crisp up” sad greens. This can sometimes work for cucumbers as well.

When it comes to root vegetables, remove the tops as soon as possible. Yes, I know farmers markets love to sell carrots, beets, turnips and radishes by the “bunch” with tops on, because it looks so beautiful and reduces bags. But I can assure you that that crisp carrot will be a limp noodle as fast as the next day if the tops are left on, even if it’s refrigerated. Remove them immediately so that the plant stops respirating all of the moisture that is making it crisp out through its leaves.

Exceptions to the “cool it off with water” rule, for me, are eggplant, peas and green beans. They all tend to rot quickly if wet. So just stash peas and beans in the fridge to chill quickly without the bath. Eggplant really wants to be at about 55 degrees, so not in the fridge and not on your countertop. Sigh. It’s the one vegetable I try to use within a day or two of picking.

I’ve also found that cucumbers benefit from a brief soak in cold water and then storage in an airtight container to keep the humidity REALLY high. Cucumbers are as much as 96% water. The ones in the grocery store are waxed to slow down water loss. If you find yours are limp within a day, try storing them in a container rather than loose in the crisper. Even with that, you are unlikely to get more than a week out of them. They are extremely perishable.

When storing produce in the fridge, humidity really does matter. I know we’re all trying our hardest to use fewer plastic bags, but keeping your produce in bags that will retain a lot of the humidity around that vegetable will go a long way to keeping it crisp and lovely for sometimes weeks. Too much water (ie puddles in the bag) can lead to rot, but not enough and your produce will be a wilted mess in days. I love these “food storage twist tie bread bags” for produce. They are found in the same aisle as the sandwich bags, often either up high or down low. I always have to look and look before I see them. Most stores have a “house” brand.

Handled correctly, your home harvested vegetables should last LONGER than vegetables you bought at the store, because they haven’t traveled thousands of miles to get to your fridge. But knowing how to handle them once picked makes all of the difference!

Resource guides for optimal vegetable handling and storage conditions:

Produce Storage Temperatures – University of Maine PDF

Roxbury Agricultural Institute Harvest Manual PDF

USDA – The Commercial Storage of Fruits, Vegetables, and Florist and Nursery Stocks PDF

© Miles Away Farm 2022, where we are happy to say that most of our produce lasts a week or more in our fridge, and some things last months! Want more content? Sign up for a monthly newsletter to your email inbox HERE.