By the time September rolls around, all but the most ardent gardeners are ready to hang up their gloves and pruning shears. The dandelion wars are long past, the transplants have flowered and gone, and the first frosts have visited. If you don’t have shrubs or foliage providing some colour, your garden may look quite barren.
However, there are many glorious fall-blooming annuals, perennials and bulbs you can use to make the third season come to life with their forms and hues. There are many hardy, never-need-to-be-dug-up bulbs that bloom in the autumn with just as much enthusiasm as their spring counterparts. Easy-to-grow colchicums are often referred to as autumn crocus because they look quite similar and grow 10 to 15 centimetres tall. However, they are more closely related to iris.
Plant them in August in average soil with lots of humus with good drainage and full sun. The corm sends up green leaves each spring that fade to yellow and die back, awaiting the burst of flowers in mid September. Mark the spot so you don’t forget. The best part is that colchicum (like crocus) will naturalize and spread over time. The double waterlily variety is a popular choice, with each double pink flower boasting more than 20 petals. Other colchicums can be white or blue violet.
Showy crocus (Crocus speciosus) is a true crocus and relative of the spring variety. Plant them in late August or early September and they will bloom in September and October. The blooms will be small the first year but will impress you with their size in subsequent seasons. Crocus are so easy to grow and inexpensive that you should plant as many as you can manage—about 100 the first year.
Adventuresome gardeners might try hardy fall cyclamen (Cyclamen hederifolium). Though advertised as hardy to Zone 6, it can grow in Atlantic gardens if you have a protected microclimate in an area of your garden. The flowers come up first, followed by foliage that is as attractive as the star-shaped blossoms. These cyclamen are one of the few flowering plants that will grow in dry shade and can be planted among the roots of trees and shrubs which in turn give the flowers protection. Follow the planting instructions for the corms carefully; they may rot if you plant them too deep.
Many annuals flop at the first frost, while others thrive in the cold. Take ornamental cabbage and kale (Brassica oleracea); cold air actually intensifies their colour. Both are extremely attractive and look well together in mass plantings and borders, plus they also look great in planters. Ornamental cabbage form heads and ornamental kale form curly, ruffled leaves in a tight rosette. You can grow these plants from seed by starting them inside in early July, or from transplants set out in early to mid August. Plant in full sun but remember, temperatures over 25°C will stunt their growth.
Named for the shape of the blossoms, snapdragons (Antirrhinum) also prefer cooler weather. When the temperature dips, they will flourish and happily add colour to beds and containers. They come in just about every shade except true blue and are available in bushy dwarf plants or taller, thinner varieties up to a metre tall.
While well known and loved (a staple in fall potted flowers), chrysanthemums can be a bit challenging to grow in your garden. “Hardy mums” can be a misnomer. Rarely do they make it through the winter to rise again in the spring. However, the potted chrysanthemums we see in every store in September will do yeoman’s work in flower beds and containers until a truly freezing frost. And we don’t have to do all the labour to get them to that point. Sometimes gardeners need to be smart as well as ardent.
For reliable and effortless performance every autumn, turn to perennials. The following three flower varieties are just a small sample, and will add colour and style when you need it most.
The first is Joe Pye Weed (Eupatorium), which is by no means a weed. It is a tall, robust plant which grows up to two metres and blooms in August and September. Ideal for the back of a border or in front of something you wish to conceal. The flowers are flat pink panicles that attract butterflies and bees. It’s great for cut flowers too. However, be forewarned—it is late to break ground in the spring, usually after most other perennials are vigorously growing, so don’t think you’ve lost it and plant something in its place.
Sneezeweed (Helenium) blossoms resemble clusters of miniature daisies and comes in a range of regal colours from bright golden yellow through orange to a rich burgundy. It is neither a weed, nor does it make you sneeze, however the dried leaves were once used in a form of snuff in centuries past. Helenium is available in dwarf and tall varieties, ranging from 45 to 90 cm. They make a long-lasting cut flower as well.
Finally, the Michaelmas daisy (Aster), so named because it blooms close to the Feast of St. Michael on September 29. Easily confused with the annual asters grown from seed or transplants for summer show, this aster is a hardy perennial you can depend on. They boast a broad colour range, dominated by blues and purples, but also pink, lavender, mauve and white, and they attract bees and butterflies. For best success plant them in moist soil and divide them every two to three years to avoid developing mildew from crowding.
Autumn gardens need not be blah or burdensome. With a little advance planning, all you’ll need is a cup of something warm while you survey your flourishing flower beds.