We are almost to the time of year in our gardens and landscapes where many of us notice a gradual decline in the color and appearance of many of our summer flowering plants. This is largely due to the fact that we plant a lot of annuals (particularly summer annuals) that tend to decline about this time of year. We are in a bit of a problem time to find color in our landscape right now since summer flowering plants are beginning to decline and it is not quite time to for winter annuals such as pansies and flowering cabbage and kale. In my opinion, that is where garden mums (or hardy mums as they are sometimes referred to) fit nicely into our fall landscapes.
Pretty soon garden mums will start showing up in local plant stores and garden centers.
Garden chrysanthemums or “mums” are among the most colorful and exciting plants that can be found growing right now and they require only a minimal amount of care. They even do well in some pretty averse conditions, and there are so many variety choices. There are literally hundreds of different cultivars with colors ranging from white, yellow, pink, bronze, red, and some colors even have a variety of shades.
Your garden mums can range in height from a mere foot or so in height to more than three feet tall depending upon the cultivar that you plant, growing conditions, and whether or not they were pinched regularly during the growing season. The best thing in my opinion about garden mums is that many of them will perenniate here in our climate. Many people treat them as short-season, fall planted annuals; however, once planted most chrysanthemums grow as perennials and will spread rapidly. You may even find that you will have to divide or thin your mums every two or three years.
Chrysanthemum’s summer foliage is deep green and their fine-textured foliage is very aromatic. Probably few people even notice the summer foliage as it is often overpowered by other more colorful plants in the landscape.
Probably the most common way to find mums right now is in fall containers or pots. Most garden centers right now are stocked with mums of all sizes and colors. When selecting your mums for fall containers, choose only plants that have healthy green foliage. Plants that look wilted have not been provided adequate water and may not perform as well as mums that have been well taken care of even when you provide them water. Mums (as do most plants growing in containers or pots) may require a little extra watering. You want the soil to stay slightly moist but do not let water stand around your mums as they hate “wet feet”. Mums are prone to get root rot if planted in an area that does not have good drainage. Also make sure you check them out for signs of disease or insect damage when you first purchase them.
Look for potted mums that have tight unopened flower buds. The fewer opened buds that your mum has, the longer it will be in bloom on your porch, deck, or patio, or in your landscape. Many of us intentionally shop for plants with open blooms so that we can see what it looks like. Instead, use the photograph on the plant label tag that comes with almost all plants bought from nurseries or garden center.
Small potted mums purchased from retail outlets can be transplanted into larger pots such as on decks or patios. You can either mix and match colors to design a colorful addition for fall or plant several mums of the same color to make a bold, impactful display.
After they are planted in pots, they are easy to care for. Keep them moist but not too wet and monitor them for insect problems such as aphids. Garden mums do have a tendency to get powdery mildew as well so keep them checked for disease as well. If insect or disease pests become a problem there are several appropriate pesticides that can be used. Just make sure you identify the problem first then follow the labeled directions.
Another option altogether is to purchase larger pots of mums and display them in large wicker baskets or containers of your choosing. A little creativity goes a long way when displaying plants. Set them out in a sunny location, keep them watered, and enjoy them. Before winter arrives, remove the plant from their pots and plant them in the ground in a sunny location. Mums planted in shade will have difficulty reblooming and usually will suffer more problems with powdery mildew. Once planted water them in and provide them with a layer of mulch to protect the root system.
Next spring when your mums begin to put on new growth, you can fertilize them with a complete fertilizer such as 5-20-20, 5-10-10, or if soil test indicates that you have enough phosphorous in the soil already, you can even use 15-0-15. The old standard 8-8-8 will work but may not provide enough phosphorous if your soil is deficient in phosphorous. There are also several water soluble fertilizers such as 20-20-20 or 15-30-15 that will work fine for smaller plantings. Discontinue any fertilization in late July when the flower buds form. You will also find it beneficial to keep new shoots pinched off to make the plant more compact and to promote more blooming. Pinching new shoots will also allow sunlight to get to the lower parts of the plant and will give you a fuller healthier mum. Do not continue to pinch off new shoots after bloom buds begin to set in late summer.
Finally, you need to control weeds around your planted mums. Mulching is a great way to help cut back on the weed problem. A layer of either pine straw, compost, shredded bark, or other organic mulch will cut down on weeds and will help hold moisture in the soil. You may also apply a pre-emergence herbicide in early spring to cut down on summer weeds. Just make sure that the herbicide product you select is labeled for use around chrysanthemums.
If you are not yet ready to give up on the colorful summer annuals (and you are certainly not alone) then deadhead them back a bit removing any spent flower blooms and any diseased or damaged foliage. Give them a little bit of water soluble fertilizer and keep them watered. As the temperatures start to drop just a bit heading into fall, you will have plenty of time for another round of blooms from your summer annuals before first frost gets here.