GardenSMART :: Getting Through the Dog Days of Summer
Getting Through the Dog Days of Summer
By Rick Schoellhorn, Proven Winners
Photographs courtesy of Proven Winners
Are the dog days of summer taking their toll on your flowers? Midsummer malaise can settle in on your container plants as the heat rises. It's not a lost cause. In this article, you'll learn how to help your plants thrive as the mercury rises.
If I was sitting in a room with no idea what time of year it was, I could probably come pretty close to guessing the month simply from the kinds of questions we get from gardeners. By midsummer, they start asking why the magic stopped in their containers and hanging baskets, and why their plants have stopped flowering. We try our best to diagnose each case as it comes along, but there are some common themes that crop up repeatedly. This article is an attempt to describe and provide solutions for common issues gardeners face in the heat of summer.
Heat tolerant varieties like Luscious® Berry Blend™ Lantana and Supertunia Vista® Fuchsia Petunia don't even break a sweat as the mercury rises.
Common Summer Issues
What you often see from midsummer into fall is a combination of issues: soil drying out, fertilizer running out, high temperatures exhausting the plants, and sometimes the accumulation of old flowers, or seed. Each of these things builds up over time and causes the plant stress.
For example, each time a plant dries out to the point of wilting, it hardens the plant a little bit, like hardening arteries in people. The stems get thinner, the water has a harder time getting through the thin stems and slowly the plant loses its ability to really power out new flowers and new growth. The same is true when the fertilizer runs out, when temperatures are extremely high, or when the plant starts to set seed. All these things cause the plant to lose strength.
Tips For Helping Your Plants Cope With Hot Summer Conditions
Try to make sure your plants are always moist (not soggy but never wilting). For many folks, a drip irrigation system can accomplish this. It can be set up on a timer to water your plants at the same time every day. The system is simple to install and simplifies your life. Once you have it, you'll wonder how you ever lived without it.
Try increasing your fertilizing frequency as we pass the midway point of summer. Give the plants a little extra food to help them deal with summer temperatures and conditions. A slow release fertilizer is good, but I think the instant energy of a water-soluble has a quicker effect.
Water your plants thoroughly. By this time of year, the potting soil frequently begins to pull away from the sides of the pot. This is bad news because it means more of your water is running around the outside of the root ball instead of percolating down through it. Thoroughly hydrating the soil can mitigate this issue. Water your container, wait thirty minutes to give the soil time to soak up water, then water it again. Repeat a few times. Alternately, put six or so inches of water in a tub, sit the container in the tub for a few hours and let it soak up water until the soil is rehydrated.
Give your plants a haircut. If things become stressful for your plants, they may try to make seed. We don't want that to happen because those seeds divert a lot of energy away from new growth. Removing the spent flowers or seed heads with a sharp pair of scissors or clippers will help the plant use its energy to make new flowers and foliage.
When The Mercury Rises In Hot Climates
Blue My Mind® Evolvulus and Diamond Frost® Euphorbia are mainstays in container recipes in warm climates.
If you live in a warm climate, late summer temperatures can reduce flowering, as most traditional summer annuals do not like temperatures above 90°F during the day or night temperatures much above 60-65°F. When temperatures get too high (especially at night) it makes it very hard for the plant to rest and build up strength and store any food. If the heat is making you really uncomfortable, many of your plants are likely uncomfortable too. As each new day begins, the plant is working off of a food deficit from the day before.
The best thing you can do in this situation is to choose to grow plants that are more heat tolerant like Luscious® Lantana and Blue My Mind® Evolvulus. You'll find more suggestions for heat and drought tolerant plants here, plants for the south here, and for all climates here. Choosing plants that are well adapted to your summer conditions is the best way to keep your garden looking beautiful through the heat of summer.
Choosing A Container Size
In hot climates, it is very hard to keep plants happy in 8-10" hanging baskets. They are the torture chamber of the hot summer garden, a tiny pot hanging outside in the wind, being cooked all day by the sun, and not enough soil for the plants' roots to find a place to grow all season long.
Be sure to use a strong support for large hanging baskets, which become very heavy when wet.
Consider buying larger hanging baskets in spring or transplanting your smaller ones into larger containers for summer. You should be able to find containers that are 14", 18", or even 20" in diameter. Larger pots with more soil volume won't dry out as fast and generally grow better all season than plants in smaller pots.
Make sure that whatever you hang those large pots from is strong enough to hold their weight when they are wet. Nobody wants to pull hooks out of the soffit or have a large container go crashing to the ground after a good rain.
Feeding Your Plants In Summer
Potting soil that contains fertilizer is great for getting your plants off to a good start in spring, but the amount of fertilizer it contains is not enough to last all summer. We recommend feeding with water-soluble plant food every third time you water your plants. If you've had a lot of rain, the fertilizer will get washed out of the container more quickly, so you'll need to fertilize again.
We also recommend that you add continuous release plant foodto the soil when you pot up your plants in spring. This type of fertilizer slowly releases food to your plants over a period of several months. We've formulated the plant foods we offer to contain special micronutrients and iron, which will keep your flowers blooming strong all season. If you store it in a tightly sealed container in a dry place like a storage shed or cabinet, it will last indefinitely.
Plants are like people. Everything they have gone through during their short lives has shaped the way they will perform in the future. Few of us can provide the perfect environment for every plant all of the time, but by making a few changes here and there, we can help our gardens continue to perform through the dog days of summer.
Contributor Bio: Dr. Rick Schoellhorn traveled most of the globe as Director of New Products for Proven Winners® before his retirement and now works as an assistant to the current Director. He loves to garden on his three acres in northern Florida and works to help Proven Winners find the best heat and humidity tolerant plants.