There are few things worse for a gardener to see than a formerly lovely container planting, withered and brown by mid-summer. Passing those sad wrecks for weeks until the owner swaps them out for Halloween decorations is pretty depressing, and leads me to believe that a lot of people are making some basic container gardening mistakes when they set out those pots and planters earlier in the summer. Luckily, there are a some preventative measures anyone can take (besides hire a part-time gardener or installing an in-ground irrigation system) to prevent the dreaded late-summer container plant die-off.
1. It’s All About the Plants
Seems pretty obvious, but plant choice is really a huge component of success when it comes to container planting in hot, sunny, or humid conditions. Many flowering annual plants will struggle in hot, sunny locations, and may require morning and afternoon watering when temperatures start creeping past the 90s. Be sure to check the sun or shade requirements of your container plants and try to avoid placing your containers in spots where they don’t get any shade (street-side, south or southwest facing, spots are especially hard on container plants).
Keep in mind that hanging plants need a little extra TLC when it gets hot because that good airflow will also dry out your containers faster. I’ve pretty much given up on putting hanging plants on my full-sun porch, mostly because I find they need more water than I can reasonably provide to survive the summer.
For true water wise container gardening, you might want to consider growing a succulent container garden, and grow plants like sedum, hens and chicks (Sempervivum), agave, or aloe in a shallow planter bowl. Even better, try growing an herb garden. Many herbs that are the mainstay of our cooking come from hot and dry locations with poor soil. Oregano (marjoram), rosemary, thyme, and sage, are very sun tolerant, and can thrive in dry soils.
2. Place your Containers where you Come and Go
I love to garden and I love to container garden, but I’m also a busy working parent, and sometimes I forget to water my plants (the horror!). Because I know my schedule and my habits, I’m very careful about how I arrange and plan to water my plants. To make watering chores easier, I put most of my container plants near my back door where I can’t neglect them. So start your container gardens off right by putting them in places where you see them or where you come and go frequently.
3. Don’t Skimp on Soil
Be sure that you’ve filled up your containers with plenty of good potting soil. If you try to save money on soil by filling your containers with rocks or other fillers, your plants will go through water faster. With more soil, those containers can retain more water, which leads to fewer waterings and healthier plants in the long run. If your once little 4-inch plants have grown to full-size and are wilting by noon, you should consider re-potting them into a larger container that can retain more water.
4. Choose Your Containers Carefully
Just as you shouldn’t skimp on soil, try to avoid pots that are too small for your plantings. You want to give your plants room to grow and develop a healthy root system. If you put your plants in under-sized pots, they will need constant watering.
If you notice that your plants seem extra thirsty despite frequent watering and plenty of soil, you may want to think about switching out the containers themselves. Terra-cotta is extremely porous and will dry out quickly. Black plastic or metal pots will heat up in full-sun and fry your roots. I prefer concrete or fiber-resin pots for my outdoor plants. These materials don’t allow water to evaporate quickly, and can generally take a beating in the winter. I keep the plastic, metal, or glazed clay for indoor plants.
5. Try Amending your Soil
A great way to give you container plants a little added insurance against heat is to add either Soil Moist, a water retaining polymer product, or mycorrhizae, a beneficial organism, to your potting mix. Soil Moist actually retains water, which gives your potting soil an extra source of moisture. Mycorrhizae latches on to the roots of your plants, enabling them to absorb more water and nutrients from the soil. Soil Moist even makes a mycorrrhiza product for container plants,
6. Going out of town? Soak ‘em and Shade ‘em!
Most healthy container plants should be able to survive a few days without water during the summer, but a week is pushing it, especially if they are in full sun, or left hanging. If you are going out of town for a week, and little rain is in the forecast, it’s a good idea to have a plan for your container gardens.
Don’t leave your plants in a saucer or a bucket filled with water! This rots and kills the roots, leaving your plants sickly and weak! Better to let them get a little dried out than drown them all-together. Instead, take down your hanging plants and move your containers out of full sun while you plant to be away. Give them one last really good soak the morning you plan on leaving, and put them in a shady spot, preferably where they can get some rain. If you have a kindly neighbor that likes to garden, ask them to give your plants a soak mid-week. Make it easier on the neighbor by filling a watering can with water and leaving it near your (hopefully shaded) containers.
To me, water wise container gardening really means figuring out ways to keep plants hydrated and healthy, with the least amount of water and work. So get your container gardens started right, and enjoy your plants as long as possible, even in the hottest of weather.
– Potting Soil 101: How to Select Soil for Container Plants and Raised Gardens Beds
– Container Gardening Guide: Tips and Design Pointers for the Beginner
– Think Outside the Box! 20 Creative Container Garden Ideas