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You have undoubtedly seen a pavilion full of unusual and magnificent dahlia blossoms if you have ever visited a state fair.
These flowers come in a dizzying array of colours and sizes, from tiny starburst blooms to massive blossoms the size of dinner plates.
If you provide adequate water, sunlight, and warmth, your dahlias should thrive.
The following are some general guidelines for growing dahlias successfully in order to ensure abundant blooms and full, robust plants, regardless of the climate in your area.
How to Grow a Dahlia Plant
The form and arrangement of dahlia petals are used to categorize the flowers themselves.
To thrive, the tubers must be planted in a sunny location with good drainage.
Dahlias require special attention from the time they are planted, beginning with the development of healthy soil and tubers.
The magnificent flowers of dahlia plants are highly addicting, and once one or two are in a garden, there will soon be many more.
Pick tubers that are in good health and are of a variety that thrives in your area.
There shouldn’t be any soft areas or mould on the outside of the tuber.
Get the garden plot ready. Although they thrive in acidic loam soil, these plants may survive in almost any non-waterlogged soil.
Dahlias are heavy feeders, so it’s best to dig down 8 to 12 inches (20.5 to 30.5 cm) and add compost to boost the porosity and nutritional density of the soil.
For optimal dahlia growth, now is the time to incorporate 1 kilogram of 5-10-15 fertiliser per 9.5 square meters of soil.
Plants of a smaller size need to be separated by 12 inches (30.5 cm), while the larger dahlia bushes will require a distance of 3 feet (1 m) between each planting.
Create a shallow trench, lay the tuber in it with the sprout facing up, and fill it with the prepared soil to a depth of three inches (7.5 cm).
Types of Dahlias
There is an infinite variety of dahlias available, each with its own unique shape, size, coloration, and texture.
Some of the most popular come in a wide range of sizes, colours, and flower patterns, and they include:
- The pink Dahlia ‘Pianella’ is considered a “cactus dahlia” with double-flowering blooms and long, rolled petals that make it look spiny (like a cactus).
- The Dahlia ‘Kelvin Floodlight’ is yellow in color and has broad flat petals that are slightly rolled at the tip. Classified as a “decorative informal,” the petals of this flower are irregularly placed, giving the bloom its full look.
- Certain types of dahlias, like Dahlia ‘Magenta Star’ feature only one row of slightly overlapping petals, taking on a much different look than fuller varieties. This particular one is named for both its color and appearance.
- The striking red Dahlia ‘Moor Place’ is deemed a “pompom dahlia” with small double-flowering blooms. The petals on this variety are round and tightly rolled, giving it a pompom look.
Dahlias require a weed-free environment. To keep the soil moist and weed-free, mulch your plants with organic material.
When the plant is 15 inches (38 cm) tall, pinch back the terminal buds to ensure strong branching and structure and boost budding.
Water your plants thoroughly. Once or twice a week, give your plants a good soaking.
To prevent their heavy blooms from sagging to the ground, large dahlias require a support system.
Spread half a cup (120 mL) of 5-10-10 around the plant’s root zone once a month with a water-soluble fertiliser, or twice throughout the growing season.
The prevention and elimination of pests is an integral part of dahlia maintenance.
Caring for Dahlia Plants in Winter
Cut down and mulch deeply, and dahlias will thrive in zone 8.
In the spring, when new growth is expected, remove the mulch.
The tubers need to be brought indoors and kept warm till spring if you live in a chilly region.
To remove the tuberous clump, dig at least a foot (30.5 cm) away from the plant.
Remove any loose dirt and let them air dry in the shade for a few days.
Clean the tubers completely and inspect them for any signs of rot or disease.
In a basket filled with damp peat moss, vermiculite, or perlite, pack healthy tubers in the upside-down position.
If you notice your tubers drying out after a month, spritz them with water.
Cure sickness by eradicating infected animals. You can also use an antifungal powder to sprinkle the tubers before putting them away.
To ensure healthy dahlia flowers, replace the tubers in the spring and continue with the following maintenance routine.
Dahlias can be grown from cuttings or overwintered tubers.
If you want to start a new crop from cuttings, you’ll have to patiently wait till your tubers begin to grow until then.
But if you divide your dahlia tubers and plant them in containers indoors before the weather warms up, you can get a head start on the growing season.
Your plants will grow and possibly bloom earlier this summer.
And since more plants mean more flowers, dividing the tubers before planting is a must.
Here’s how to propagate dahlias from tubers:
- You will need a 5-gallon bucket, a trowel, garden shears or pruners, potting soil with vermiculite, peat, large growing containers, and overwintered dahlia tubers.
- In a bucket, combine dirt and peat and moisten with just enough water to work. Spread the soil out across many plant pots. (While the tubers are establishing their root system and sending up their first sprouts, it is crucial that the soil be kept moist.)
- To figure out which tubers in a group have eyes, you should look at them closely (or, if you can’t, leave the group in a warm, moist place for a few days, at which point the eyes may expand and sprout). The tubers should be separated from the clump at the base. Several tubers can be dug up from each clump, but how many depends on how big the clump is, to begin with.
- Make a hole in the ground in the center of each pot (2 to 3 inches deep for small tubers, and 6 to 7 inches deep for larger ones). You can plant individual tubers sideways in the hole with the eye facing up, or you can plant tuber clumps vertically with at least an inch of soil covering the stem from the previous year.
- Keep the soil moist but not dripping wet as you wait for the tubers to sprout in a sunny window. As soon as three sets of branches have emerged from the seedling, a portion of the top should be pinched off.
- Dahlias should be planted in the garden in the late spring when the soil is warm enough to do so, with 3 to 4 feet of space between plants (for larger types) and 2 to 3 feet between rows.
Here’s how to propagate dahlias from cuttings:
- Get yourself a 4-inch pot, some rooting hormone powder, potting soil, alcohol pads, and a sharp knife.
- There should be at least three inches of growth before you harvest your tubers. Then, use the alcohol pads to thoroughly disinfect your knife. Hang it up to dry. The next step is to cut into the tuber, halfway between where the sprout was and where it is now.
- Reduce the number of leaves at the bottom by laying the cutting on a hard surface and cutting them off. You should fill your pots with potting soil and then make three or four small holes along the edge of each pot.
- Fill the hole back up with soil after dipping the end of your cutting into the hormone powder and inserting it into the hole. It is necessary to make additional holes and cuts.
- Plant the container in a sunny window after you’ve given it a good soaking and allowed the excess water to drain. Preserve the soil moisture.
- A week to three at the most should be enough time for your cuttings to take root. Plant them in your garden bed at the appropriate spacing once they have established healthy growth and the weather has warmed up.
How to Grow Dahlias From Seed
Purchase seeds for dahlias at your local nursery and plant them in your garden. or by sowing seeds saved from the previous season.
You can do this by beginning the seeds indoors four to five weeks before the last frost, using a seed starting mix and a seed tray.
Place the pan in direct sunlight and moisten the soil occasionally.
Once the seeds have germinated, they should be given a few days to grow a full set of leaves before being transplanted into their own cell or tiny pot.
The soil should be kept moist. Transplant the seedlings outside as soon as the soil temperature reaches 65 to 70 degrees Fahrenheit.
Potting and Repotting
The larger the container, the better it is for growing dahlias in containers.
Use a container that is at least 12 inches in depth and width as a general rule of thumb.
There should be no need to repot your dahlias during the growing season if you use containers of this size.
You may ensure healthy development and an abundance of blossoms by moving your containers outdoors throughout the summer and staking the stems.
There are space-saving compact dahlia cultivars you may cultivate as well.
Common Pests & Plant Diseases
Dahlias are a favorite food of common garden pests like slugs, earwigs, caterpillars, and thrips.
When leaves are young and vulnerable, slugs can do significant damage.
Slugs are rarely an issue once the plants have reached maturity.
For some gardeners, deer are a constant problem, while others swear the animals stay away from their dahlias.
Whether or whether this is the case may be determined only by the abundance or scarcity of alternative snacking options in your garden. Just in case, make sure your flowers are safe.
Powdery mildew and other fungal diseases can also affect dahlias.
Don’t forget to keep the leaves dry and give your plants plenty of room to breathe by not crowding them too closely together.
Natural remedies like neem oil should be used to combat infections if they are detected.
How to Get Dahlias to Bloom
Make use of stakes and rope to keep your dahlias standing tall and proud for optimal flowering.
To encourage continuous blooming, dahlias should be fertilised every two weeks.
With a high-phosphorus organic fertiliser, your plants will have a good flowering rate and sturdy stems.
Remember to water your dahlia bed often, especially if it contains huge varieties, and to mulch the bottom to keep in moisture.
Expect dahlias to bloom in a matter of months. Last but not least, once the blossoms have faded, be careful to deadhead your plants.
Flowers will grow more abundantly if spent blossoms are promptly removed.
Common Problems with Dahlias
Overwatering dahlia beds, or those with poor drainage and heavy soil, can lead to stem rot.
Prevent this by amending your soil every time before planting and by never letting water sit in your garden.
Even dahlias tend to collapse and wilt in the June sun. The plant is responding to stress, therefore this is not necessarily a bad thing.
When the sun goes down, dahlias that were planted in a moist bed should sprout back up.