Dahlias are a rewarding choice for your summer flower bed. Not only do they add visual interest with their showstopping blooms, but they also hold those blooms well when cut. If you love the idea of fresh flowers in your home, growing dahlias is an easy and inexpensive way to make that happen.
The range of dahlias you have to choose from is amazing, with blooms barely an inch across to ones larger than your dinner plate. The choice in colors is wide as well, making it easy to find something that will complement your existing landscaping.
For the strongest, hardiest dahlias, plant your seeds or seedlings in well-drained soil. Wait until the soil warms in the spring, as this species does not tolerate frost at all. Even with this late planting, expect to see dahlias in full bloom midway through the summer.
Dahlias are grown from tubers. Dig a hole at least six inches deep, and work in some compost. If the soil is heavy clay or otherwise doesn't drain well, adding some fine gravel to the mix can help your dahlias remain healthy. Once you have prepared the hole, backfill it with the soil and compost mixture until it's around 4 inches deep. Place the tuber in the hole and cover it with soil.
Dahlias come in a range of sizes. The larger your chosen variety will get, the further apart each tuber should be spaced. Generally, plant dahlias between one and three feet apart. One thing to keep in mind is that the taller varieties of dahlia will need additional support when they are in bloom. Place the tubers so you can easily stake the plant as they grow.
Dahlias do best in areas where they receive full sun. Look for a location that gets a minimum of 6 hours of direct sunlight daily. They can suffer under intense sun exposure, so an area that gets full morning sun is perfect.
Known as tender perennials, dahlias should be treated as annuals for people who live north of zone 7.
Dahlias do not tolerate overwatering. Do not water your plants at all until they emerge from the soil. Then a deep watering twice or, at most, three times a week will provide what they need in most cases. If you live in an area where the weather is extremely hot and dry, you may need to water more frequently, but err on the drier side. Overwatering can quickly lead to root rot.
Dahlias are susceptible to various pests, including aphids, earwigs, mites, slugs, and snails. Talk to your local extension service for recommendations on pest sprays for your area. You can also set out bait traps to capture slugs and snails.
A larger pest to worry about is deer. Deer find dahlias tasty and can quickly graze your plants to the ground. Planting deer-resistant choices — such as rosemary or mint — around your dahlias may help somewhat, but if deer are an issue in your area, these pretty plants might not be the best choice for you.
Dahlias may develop powdery mildew during the fall. A preventative application of neem oil in mid-to-late summer will help to protect them. You can also guard dahlias from powdery mildew and other diseases by avoiding the leaves when you water and thinning out your plants if they become dense. Air circulation will ensure moisture evaporates quickly from the leaves and stems, minimizing the risk of mildew.
If you grow taller varieties of dahlias, prepare to stake them before their heavy blooms start bending the stalks. Catching them early ensures the stems don't become damaged trying to support their weight.
Dahlias respond well to fertilization, rewarding you with showy blooms and massive growth. Select a fertilizer low in nitrogen and apply it throughout the growing season, with the final application at the end of August.
Dahlia tubers will not survive if they're left in the soil once the ground freezes. Dig them up when the foliage begins to die back and turn brown, but be careful not to damage the tuber. Shake them gently to remove excess soil, then examine them. Use a clean, sharp knife to remove any rotten or damaged areas, then leave them outside to dry.
Place the dried tubers in a container filled with fluffy packing material for protection. Dry sand, packaging peanuts, and vermiculite are all good choices. Place the container in a ventilated spot that will stay cool but frost-free through the winter.
In the spring, when you are ready to plant, you will find smaller offshoot clumps that you can easily separate from the main parent clump. Gently disassemble the clumps and plant them along with the rest. As long as each tuber has a piece of the crown — known as an eye — it will develop into a plant.
Although grown for their beauty, dahlias are also edible — both the tubers and the flowers. The taste is compared to a cross between a radish and potato.
While humans and deer can enjoy this treat, however, they are poisonous to pets. Cats and dogs will usually leave this species alone, but if your furbaby exhibits symptoms like vomiting, diarrhea, a rash, or blisters, call poison control or your veterinarian right away. If your pet is overly interested in your dahlias, you may need to get rid of them or place them somewhere she can't reach.
Most dahlias are great for bringing bees to your garden, although the ones with more closed-off petals are less attractive to pollen collectors.
There are many varieties of dahlias to choose from. They come in a range of colors and sizes, and you are sure to find some that suit your tastes perfectly.
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