Article by Lorna Kring of Gardeners Path
It’s a sad sight to see. And it happens every year.
Planters and containers that were once rich with color and foliage slowly fade and fail, becoming worn out and tired-looking by the time mid-summer rolls around.
And the higher the temperatures climb, the more those pretty blossoms and plump leaves shrivel and disappear.
Well, this doesn’t have to be your tale of woe this year. You can help your containers to flourish with vibrant good health all summer long just by doing one little thing differently.
Sounds good, right? It is! But first, let’s take a look at all of the steps that will help your pots and containers to put on a peacock-worthy display throughout the season this year.
Here’s a brief review of the steps that you can take to create and maintain a brilliant display all summer long.
1. PICK THE PERFECT POT
The first step for a robust planter is to choose the correct pot size. This is determined by a few different factors.
A planter that’s too small will crowd roots, resulting in a scarcity of water, oxygen, and nutrients that are vital for healthy, vigorous growth.
Containers that are too big can result in overly moist soil, cutting off oxygen and drowning the roots. And the cool, moist soil often found in planters with too much room is also a welcome mat for plant problems. Fungal growth such as powdery mildew and leaf spot are common visitors, as are damping off and root or stem rot.
Bedding plants, seasonal kitchen herbs, annuals, and bulbs can all be arranged a little closer and tighter than plants in the ground, to make an impressive and healthy visual display.
So, if the recommended spacing is, say, 10-12 inches, item that thrive in containers can be planted about 6-8 inches apart.
And as a general rule, if their normal growth is 10-12 inches tall, you’ll want a pot that’s a bit more than half that size, or around 6-8 inches in diameter. For plants that grow from 24-36 inches in height, a larger container around 24 inches in diameter would be appropriate.
Your pot will need drainage holes with adequate drainage material on the bottom, to allow excess water to flow away easily.
Inverting a smaller plastic pot over the drainage holes will work if adding more weight is an issue, as will using packing chips or peanuts. Gravel, pebbles, pieces of broken pottery, nut shells, pinecones, sticks, and coffee filters can all been used for drainage.
As a rule of (green) thumb, container plants don’t like to have wet feet – that is, having their roots sitting in water makes them unhappy.
A soggy root environment will cause most bedding plants to sulk and underperform. Or the roots may simply rot, which is not conducive for pretty planters!
Drainage is also needed to provide aeration for potted roots, as it’s harder for them to “breathe” and access oxygen in a container than it is for plants in the ground.
2. PLANT WITH A PLAN
For many of us, the garden center has the same effect as a candy shop does on kids. “I want some of these, and six of those, and oh, I need a whole flat of the pretty pink ones…” And as we all know, impulse buying does not always mean we’ve made the best choices!
So, a little discernment (and self-discipline!) will help in selecting plants that will produce the best results for your location.
Choose plants that will thrive in your particular climate and light conditions. And if you like to mix plants together in one pot, select ones that have similar requirements for water and light.
Adding some foliage plants will help to fill out your pots, and they also provide an element of unity – pulling the overall picture together for greater visual appeal.
The addition of plants with varying heights and bloom times will also add a dynamic visual interest to your potted gardenscape, changing as the season progresses.
Summer flowering bulbs like gladiolas, canna lilies, arums, and caladiums will extend the season, providing fresh color and interest while earlier bloomers take a rest.
3. PROVIDE NUTRIENT-RICH SOIL
How good is it to be a fully grown adult and still be able to play in the dirt?!
However, we’re not serving up mud pies anymore. As garden stewards, we need to provide a nutrient-rich environment to ensure that our bedding plants thrive.
Amending your soil with about 20-25% finished compost or well-rotted manure improves the soil in a few different ways. It develops the soil’s tilth, or body structure, which helps with the retention of moisture and nutrients, and reduces soil compaction.
Container soil is best when it has some moisture-retaining materials in the mix, such as perlite, vermiculite, sphagnum moss, or peat, at about 20% of the volume. It also needs nutrient-rich materials such as compost or manure.
Amending your soil with about 20-25% finished compost or well-rotted manure improves the soil in a few different ways. It develops the soil’s tilth, or body structure, which helps with the retention of moisture and nutrients, and reduces soil compaction. Plus, it can act as an equalizer for soils that have lost their pH neutrality.
Use a large bin, wheelbarrow, or a layer of plastic on the ground to mix up all of your ingredients in batches large enough to accommodate several pots. And if you purchase a growing mix, ensure that the texture is light and loose enough to provide ample drainage while still retaining some moisture.
If you like to recycle last year’s container soil, replace at least half to two-thirds with fresh soil, recycling any depleted dirt into your compost bin.
Of course, you should never recycle or compost any soil that has had diseased or failing plants grown in it. Spores, fungus, mites, and other unfriendlies can live on in the soil long after the plants have been removed – and they can be nestled in the dirt even with plants that look healthy. A safer option is to use fresh soil for each pot.
4. GIVE THEM A LONG, TALL DRINK OF WATER
By the time summer arrives, containers in a sunny location require frequent, even daily, watering when it’s hot out.
However, not all pots require watering at the same time. Differences in light exposure, pot size, and plant size determine how often water is required.
Strong, healthy plants need strong, healthy root systems, which are developed by deep, slow watering. Light watering will develop small, shallow roots just under the surface. This leaves the larger roots at the bottom deprived of moisture, which causes plants to become dehydrated and fail.
Water slowly to ensure the entire root ball, including the deepest roots, gets a good drink, or just until water starts to emerge from the drainage holes.
5. GROOM BI-WEEKLY
During the growing season, give your containers a light grooming session every couple of weeks.
Deadhead spent blossoms, cut back straggly stems, and if needed, replace any plants that have given up.
Container gardening has no more pests or problems associated with it than ground plantings. But due to their close quarters and reduced air circulation, the spread of fungi and pests can be rapid.
To keep remaining plants free of infestation, any diseased specimens need to be removed pronto. Difficult to control, some prevention can be accomplished with regular spraying of new foliage with neem oil.
As the summer progresses, you can also freshen your containers with the addition of late-season performers like mums, autumn sedums, asters, calendula, and violas.
And now, for the trick we’ve all been waiting for…
6. THE MOST IMPORTANT STEP: FERTILIZE, AND FERTILIZE AGAIN
That’s it. When practiced regularly, this is the one simple tip that will significantly improve the performance and appearance of your planters and containers.
The addition of a slow-release fertilizer is always a good idea, and every planting should be finished off with granules that will feed slowly. A better idea is to give your containers a diluted drink of water-soluble fertilizer every two weeks, and even weekly for small pots that require frequent watering.
Every time a container is watered correctly, to the point of water coming from the drainage holes, it flushes nutrients out of the pot and away from the roots. This is problematic…
The reason is simple. Every time a container is watered correctly, to the point of water coming from the drainage holes, it flushes nutrients out of the pot and away from the roots. This is problematic, because unlike plants grown in the ground that can expand to find food, the roots are limited to an area within the container walls, with no access to fresh dirt and nutrition.
The answer is to supplement with a diluted solution of an all-purpose, water-soluble fertilizer on a weekly or bi-weekly basis. A general purpose fertilizer of 24-8-16 (24% nitrogen, 8% phosphorous, and 16% potassium) will maintain and feed your plants in pretty much any environment, but specific formulas (such as for tomatoes or annuals) may be selected to cater specifically to your chosen plantings.
Take care to heed the word dilute. Too much fertilizer is just as bad (if not worse) than too little, and will cause plants to grow and display fast and bright – but they’ll also burn out and fail quickly, too.
Over-fertilizing can cause plant leaves to turn yellow or brown, and damages roots. “Burning” is caused by the naturally occurring salts in fertilizers, which draw moisture out of the plant. Too much, and the most susceptible areas of the thin tips and edges will brown first, followed by the entire leaf.
To find the Goldilocks zone for fertilizing containers, take the recommended dosage for the product you’re using, and divide it by how frequently you’ll be fertilizing. For example, if the recommended amount is one “scoop” per month, divide the amount by 2 for bi-weekly feedings, and by 4 for weekly fertilizing. Mix into a full watering can and apply to moist soil.
Quick and easy, just as tips and tricks should be!
BE THE WATCHER
As caretaker of your lovely container gardenscape, you’ll also want to keep an eye on your plants to see how they’re responding to your care and maintenance regime. If they’re not flourishing, they’ll communicate their needs by their appearance.
So remember, to retain their healthy good looks for the entire season, feed your planters more frequently, but with weaker doses of a water-soluble fertilizer. This is simple but effective, and you’ll be thrilled with the results.