Container gardens Gardening Watering

As Summer Progresses, Water Containers More

As planters fill in, they’ll need more water. Photo: Share Bear, Wikimedia Commons

More people are growing plants in containers than ever before. Balconies, decks, windowsills and even roof tops are now greening up as millions of ardent and often fairly novice gardeners cover them with pots of all descriptions full of vegetables, flowers, herbs and even trees and shrubs.

It’s always wise to keep a watering can or two filled for “watering emergencies”. Photo: properlyrooted.com

So, if you’ve been caring for your potted garden since spring, you should be noticing something: it needs more and more water as the summer progresses. When a once-a-week watering might have been enough for a large, deep container earlier in the season, that might be twice a week in July, or even three times in August.

That’s only partly because the air is usually hotter in full summer than in spring. The real reason is … your plants are growing. And keep growing. And flowering. And producing edible bits. Most don’t stop (or shouldn’t) until fall. That means you have to adjust your watering habits accordingly.

Water any way you want, but don’t let your plants wilt. Photo: dramm.com

Most of you will notice that, although your container garden probably looked a bit empty in the spring, it’s full, even overgrown, by midsummer, as plants jostle for space. And as they struggle for more light, they’re also fighting over water.

Not that you have to change your methods. If you water using a watering can, keep on with it. But you’ll need to fill it up and water more often. Same goes for hose watering: linger a bit longer while you water; it will take more H20 to evenly humidify all those roots. 

Even if you use drip irrigation, you have to adjust to the increased water need. Photo: OklahomaGardening

Your thing is drip irrigation? Not a problem … but adjust the frequency or the duration of each session. Your containers may need double or triple the water they needed last spring.

Timing

Your plants may be big and thirsty, but you still have to take the weather into account. Hot days and dry air parch plants, but, depending on your climate, summer can also bring heavy rains that take care of watering for you … for a while. And there can be cooler weather or very humid air, both of which reduce watering needs.

So, you can’t really set a strict watering schedule. Doubly so in that, on the same balcony or deck, some containers (small pots, those in full sun and those containing big plants) dry out faster than others (large containers, ones in shade and those containing few or small plants). 

Your finger: nature’s water meter. Photo: rking@duluthnews.com

Ideally, check your plants daily. Stick your finger into the soil to the second digit. If it’s dry, water abundantly, soaking the whole root ball. If not, try again the following day. 

While you’re checking, look for signs of insects and disease and react rapidly if you find any. Also, prune out dead or dying leaves and, if you’re into deadheading, cut faded flowers too. Pull out any weeds as well.  

Fertilize While You Water

Container gardens need more fertilizer than in-ground gardens because a) we usually stuff more plants into the same amount of container space than in the ground and b) minerals readily leach out of pots whereas they stay within the root zone area of garden plants. 

Water in a soluble fertilizer. Photo: acti-sol.ca

A lot of gardeners add slow-release fertilizer at planting time, then complete with a water-soluble fertilizer as summer progresses. By the time your container has filled in, you should be considering watering in a solution of your favorite fertilizer at about ¼ the recommended rate about every two weeks.

Which fertilizer? Why make life complicated by buying dozens of fertilizers, each supposedly designed with a certain group of plants in mind? The truth is that any fertilizer will do the job. Just use whatever you have on hand, even if that means applying lawn fertilizer to container vegetables. They really don’t care!


Don’t knock yourself out over mid and late summer container care. Just make it part of your daily routine to wander lazily about and check your plants, keeping that hose or watering can at hand when you do so. Relax and enjoy!

Larry Hodgson is one of Canada’s best-known garden communicators. He has notably been editor-in-chief of HousePlant Magazine, Fleurs, Plantes et Jardins, À Fleur de Pot and Houseplant Forum magazines and is currently the garden correspondent for Le Soleil and radio garden commentator for CKIA-FM Radio. He has written for many garden publications in both the United States and Canada, including Canadian Gardening, Harrowsmith, Horticulture, Fine Gardening and Organic Gardening. He also speaks frequently to horticultural groups throughout Canada and the U.S. His book credits include The Garden Lover’s Guide to Canada, Complete Guide to Houseplants, Making the Most of Shade, Perennials for Every Purpose, Annuals for Every Purpose, and Houseplants for Dummies, as well as nearly 60 other titles in English and French. He is a past president of the Garden Writers Association (now Garden Communicators International) and the winner of the prestigious 2006 Garden Media Promoter Award offered by the Perennial Plant Association. He resides in Quebec City, Quebec, Canada.

3 comments on “As Summer Progresses, Water Containers More

  1. Wicked hot summer here, and now we are in a severe drought so I’ve had to start a little ‘early’ fall cleanup and reduce some containers that were fading.

    • We had a wicked hot July here, but temps have dropped to cool (like, you need a jacket outdoors) and the rain is back – lots and lots of it.

  2. In a chaparral or desert climate, there is less humidity during summer, and the lack of humidity is not interrupted (normally) by rain or more humid weather. The days are also slightly longer.

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