Chrysanthemums have enjoyed a rich history of over 2,500 years in cultivation starting in Asia. There are now more than 5000 named varieties grown all over the world. We still have a large selection of beautiful mums in a variety of colors, sizes and shapes. Below is some helpful information about Chrysanthemums.
Why are chrysanthemums listed under different names in the gardening books? New techniques and technologies have enabled botanists to classify plants more accurately than ever before, resulting in lots of name changes and some confusion. What was for years classified as Chrysanthemum x morifolium is now classified as Dendranthema x grandiflora. They also go by several common names such as garden mums, chrysanthemums and hardy mums.
Are mums truly perennial? I’ve had problems with wintering them successfully. All garden mums are perennials, but not necessarily in our climate. In fact, the University of Minnesota feels that while some mums winter successfully some winters, there are no cultivars that are reliably winter hardy here. However, mums are inexpensive, can provide you with hundreds of blooms on each plant and are well worth growing as an annual. If they come back next year, it’s a bonus.
Should mums be planted in the spring or fall? There are advantages and disadvantages to each. Spring plantings develop a more extensive root system and are more likely to winter successfully than those planted later in the growing season. On the other hand, planting your mums in late summer allows you to replace some of your early blooming annuals with plants just ready to burst into full color. Mums planted in fall have already been pinched for the season.
Are there different types of mums? Mums are usually grouped by the shape of the flower such as decorative, cushion, daisy, pompom, button, anemone, spoon, spider and quill. There are also several types of large ‘football’ mums. The most common variety grown in our area is the decorative mum. They have large double or semi-double blooms on medium height plants.
Don’t mums bloom at different times during the season? Each mum you choose should be labeled as to when it blooms in the fall. The tag will say either early, mid or late. Sometimes it will be indicated by E, M or L. Very few late m
ums are grown in our area because our season is too short. Mum season extends at least 6 weeks, from mid- August to late September. Since mums that have been grown outdoors can take frost, you will often see mums blooming long after your other annuals and perennials have died.
If mums are fall bloomers, why are they in flower when I buy the young plants in spring? Mums are naturally fall bloomers. Their blooming is related to the nights getting longer. Garden mums you buy in spring are grown while the nights are still long enough to trigger their blooms. Buying them in bloom in spring enables you to choose forms and color early in the season. If you let them, these plants will bloom for a few weeks early in the season, often exhausting the plant. Ideally, you want to pinch off all the blooms and buds when you buy the mums to
encourage vegetative growth and root development for fall bloom.
Can I do anything to affect the season of bloom? There is no practical way for a home gardener to make a mum bloom earlier than normal. By pinching a week or two later than normal, you can make an early mum bloom later, with the mid-season varieties.
Is pinching how I keep my chrysanthemums compact? If you want your mums to be compact and full of blooms, you will have to pinch them. Mums develop buds at the ends of branches and by pinching them; you encourage many more branches to develop.
Exactly where do I pinch the branches? It’s best to pinch about 1/4″ above a set of leaves about midway up the stem, but it doesn’t have to be precise. Try to avoid damaging the little side shoots developing where the leaves meet the stem. On young tender plants use your fingernails. If not, use a narrow-bladed scissors or pruning shear.
How often will they need pinching? Your first pinch should be as soon as there is about 5-6 inches of growth. Then, once they have branched and put on another 5-6 inches of new growth, pinch them again. Depending on the season, you may be able to get in a third pinch. To have mums bloom on schedule, avoid pinching any later than July 10.
Do all mums make good cut flowers? Yes they do. They often last for weeks, especially if you freshen the water and keep them out of direct sun. Mums that you buy as cut flowers have longer stems. Longer stems can be encouraged by pinching the plants only once in early summer.
Can I grow the big football (exhibition) mums? Football mums grow well here, but they are not winter hardy and do take more work.
Will pinching affect the size of the blooms or just the number? By limiting the number of branches, you will get larger blooms. You can also encourage larger blooms by pinching less often or disbudding the branches. To disbud, you remove the little branches that appear at the leaf axils every 10 days or so. This will give you the biggest flowers, but there won’t be very many. Mums that are being encouraged to develop large blooms should be staked or supported in some manner.
How much sun and what kind of soil do mums need? To do their best, mums need full sun. Too little sun will result in tall, leggy plants that won’t bloom as prolifically. Mums will grow in almost any well-drained soil, but would prefer it to have lots of organic matter.
How often should I fertilize my mums? What should I use? Mums respond well to frequent applications of watersoluble fertilizers. As soon as they are several inches tall, begin feeding them every two weeks until they begin to form buds.
Do they have any problems with insects or disease? Mums will occasionally have problems with aphids, inchworms, spittlebug and four-lined plant bugs. During cold wet seasons, they can have some problems with fungus.These problems can easily be treated with most insecticides and fungicides. If you notice a problem, bring in a sample and let us help you determine what would be most effective.
What should I do after the mum has finished blooming? After the blooms have faded or the plant has been frosted, trim off the old blooms but do not cut back the plant. Studies on winter hardiness of mums have shown they are hardier if they are not cut back in fall. Wait to mulch the area until the ground is close to freezing. In our area, that is usually about Thanksgiving. Use loose mulch such as hay or straw and apply it about 6 inches thick. A strawberry basket over the crowns keeps out wet mulch.
Chrysanthemums can add beauty to any landscape and have been recognized by Salinas as its very own official flower! Ask a professional at McShane’s Nursery and Landscape Supply for more information about chrysanthemums!