How to Grow Dahlias
Determine which of the dahlia varieties you would like to grow., Purchase fresh dahlia tubers., Grow dahlias outdoors in zones 7 to 10., Plant dahlias late in the spring., Select a location with full sun and low wind., Plant your dahlias in...
Step-by-Step Guide
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Step 1: Determine which of the dahlia varieties you would like to grow.
Dahlia is a large plant family, and you’ll need to decide which size of plant will best suit your growing space.
Unlike other popular flowers, dahlias come in three main categories: large (including the popular “Dinnerplate” variety), medium, and small.
Dahlia flowers also vary in color and size, although the size is usually proportionate to the overall size of the dahlia plant.Large dahlias can grow from 3–4 feet (1–1.2 meters) tall.
Medium dahlias (also known as border dahlias) will reach between 1–2 feet (0.3–0.6 meters) in height.
Small dahlias will only reach between 10–20 inches (25–50 cm) in height. -
Step 2: Purchase fresh dahlia tubers.
You should be able to find dahlia tubers for sale at any reputable plant nursery or garden center.
Due to the variety and diversity among types of dahlias, be sure to ask the sales staff for assistance.
They’ll be able to help you determine which tubers will produce which size and color of blossoms.
If you live in a remote location and do not have access to a nearby plant nursery, you can purchase the dahlia tubers online instead.
Check the websites for major online plant retailers including Eden Brothers, Dahlia Barn, Dahlias.com, or Harris Seeds. , Dahlias thrive in warm, sunny climates, and are hearty in planting zones 8 and
9.If you live in the United States, this means that dahlias will not survive the winter if you live north of Kansas and east of western Idaho.
If you live in zones 1–6, you will need to plant your dahlias indoors.
Dahlias don’t do well in long, hot summers, so if you live in zone 10, you may need to cover outdoor dahlias or bring them indoors in summer.If you live in zone 7, dahlias may be able to survive an outdoor winter if you pack mulch around the base of the flowers. , Wait to plant dahlias until your region no longer has a threat of frost.
If you have a thermometer that can be used to measure ground temperature, that can guide your planting time.
Do not plant the dahlias if the ground temperature is below 60°F (16°C), or the dahlias may not grow.If you plant the dahlias early (e.g. in March or April) and another frost comes, the tubers will die. , Dahlias thrive in full sun, and should be planted in a location where they will be in direct sunlight for at least 6 to 8 hours a day.
Dahlias also need to be protected from the wind, so plant them in a protected area.
Their large flowers can become heavy when mature, and can snap off in a stiff breeze., Soil that drains well will not form puddles, and will allow the tubers to absorb what liquid they need without drowning.If you already have a garden or a section of your yard with well-drained soil, plant your dahlias there.
If you’re concerned that the soil may not drain well, add sand to your soil to improve your garden’s drainage.
Do this at the same time that you’re adding the compost or manure.
If your soil is clay heavy, work peat moss or compost into the soil to loosen it.
This can make it easier to plant dahlias. , Use a spade to work manure or another fertilizer into your garden a couple of weeks prior to growing dahlias.
It’s necessary to prepare your soil to grow dahlias before planting the tubers.
Adding fully rotted compost or another fertilizer type to the soil will encourage the plants to grow well and bloom quickly., Each hole should be about 4 inches (10.16 cm) deep.When digging the holes, leave enough space between the plants that growing dahlias will not choke one another or steal nutrients from one another.
For smaller varieties, leave 2 feet (0.61 m) between holes.
For medium or giant dahlias, leave 2 to 3 feet (0.61 to
0.91 m) between holes., Dahlias need plenty of fertilizer to grow successfully, and adding organic material to the soil ahead of time will help ensure that the plants grow well.
Scoop a small handful of compost and bone meal into each of the holes, and add a small scoop of dry fertilizer.You can purchase ground bone meal at a local plant nursery or gardening center.
If you do not already own compost and fertilizer, you can purchase them from a large gardening center or from a landscaping outlet. , Drop a single tuber in each hole, and then fill with soil.
You can expect to see the tubers growing in 2 or 3 weeks.Be sure the growing point of the tuber faces upward before you cover it with soil.
After each dahlia has been planted, water the soil lightly. , Do not water the dahlia tubers before you can see growth, or you’ll likely drown the plant.
Wait until you can see sprouts above the soil, and then water the dahlias only in the morning.
This will prevent the water from evaporating if you live in a hot zone.It’s not necessary to water the dahlias every day.
Keep an eye on the plants and, when they begin to look a little wilted, water them generously. , Fertilizers can help your dahlias grow quickly and well.
They’ll thrive if given a low-nitrogen liquid fertilizer, which is the type most commonly used for vegetable gardens.
You can fertilize the dahlias once they begin to sprout.
Continue by fertilizing the plants about once each month until August.You can purchase low-nitrogen liquid fertilizer at a local garden center or plant nursery.
It may even be available at a supermarket.
Look for a 5-10-10 or 10-20-20 mixture. , Tall dahlias may not be strong enough to support the weight of their own stems and flowers.
Prevent these plants from falling over by tying them to stakes shortly after they begin to grow.
You can use a thin piece of regular string or twine to fasten the stem to the stake.You can use a plain wooden stake or dowel to secure the dahlias.
If you’d rather have a more decorative garden, purchase a cylindrical tomato cage and let the dahlia use it as a support. , Once a dahlia plant begins to develop several bunches of bushy leaves, pinch off all of the flower buds, except for the bud at the very top of the plant.
This is known as the terminal bud and will produce a very large flower if the other buds are removed.If you’re not concerned with producing large, impressive flowers (of the type that would be entered in a flower competition), you don’t need to disbud the plant.
Simply let the buds grow where they will. -
Step 3: Grow dahlias outdoors in zones 7 to 10.
-
Step 4: Plant dahlias late in the spring.
-
Step 5: Select a location with full sun and low wind.
-
Step 6: Plant your dahlias in well-drained
-
Step 7: fertile soil.
-
Step 8: Add compost or manure to your soil.
-
Step 9: Dig holes for the dahlias tubers.
-
Step 10: Fertilize the holes before planting the dahlias.
-
Step 11: Plant dahlias in the prepared holes.
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Step 12: Water and fertilize dahlias once sprouts show.
-
Step 13: Fertilize with a low-nitrogen liquid fertilizer.
-
Step 14: Stake growing dahlias if you are using taller varieties.
-
Step 15: Disbud the dahlias to produce a single
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Step 16: large bloom.
Detailed Guide
Dahlia is a large plant family, and you’ll need to decide which size of plant will best suit your growing space.
Unlike other popular flowers, dahlias come in three main categories: large (including the popular “Dinnerplate” variety), medium, and small.
Dahlia flowers also vary in color and size, although the size is usually proportionate to the overall size of the dahlia plant.Large dahlias can grow from 3–4 feet (1–1.2 meters) tall.
Medium dahlias (also known as border dahlias) will reach between 1–2 feet (0.3–0.6 meters) in height.
Small dahlias will only reach between 10–20 inches (25–50 cm) in height.
You should be able to find dahlia tubers for sale at any reputable plant nursery or garden center.
Due to the variety and diversity among types of dahlias, be sure to ask the sales staff for assistance.
They’ll be able to help you determine which tubers will produce which size and color of blossoms.
If you live in a remote location and do not have access to a nearby plant nursery, you can purchase the dahlia tubers online instead.
Check the websites for major online plant retailers including Eden Brothers, Dahlia Barn, Dahlias.com, or Harris Seeds. , Dahlias thrive in warm, sunny climates, and are hearty in planting zones 8 and
9.If you live in the United States, this means that dahlias will not survive the winter if you live north of Kansas and east of western Idaho.
If you live in zones 1–6, you will need to plant your dahlias indoors.
Dahlias don’t do well in long, hot summers, so if you live in zone 10, you may need to cover outdoor dahlias or bring them indoors in summer.If you live in zone 7, dahlias may be able to survive an outdoor winter if you pack mulch around the base of the flowers. , Wait to plant dahlias until your region no longer has a threat of frost.
If you have a thermometer that can be used to measure ground temperature, that can guide your planting time.
Do not plant the dahlias if the ground temperature is below 60°F (16°C), or the dahlias may not grow.If you plant the dahlias early (e.g. in March or April) and another frost comes, the tubers will die. , Dahlias thrive in full sun, and should be planted in a location where they will be in direct sunlight for at least 6 to 8 hours a day.
Dahlias also need to be protected from the wind, so plant them in a protected area.
Their large flowers can become heavy when mature, and can snap off in a stiff breeze., Soil that drains well will not form puddles, and will allow the tubers to absorb what liquid they need without drowning.If you already have a garden or a section of your yard with well-drained soil, plant your dahlias there.
If you’re concerned that the soil may not drain well, add sand to your soil to improve your garden’s drainage.
Do this at the same time that you’re adding the compost or manure.
If your soil is clay heavy, work peat moss or compost into the soil to loosen it.
This can make it easier to plant dahlias. , Use a spade to work manure or another fertilizer into your garden a couple of weeks prior to growing dahlias.
It’s necessary to prepare your soil to grow dahlias before planting the tubers.
Adding fully rotted compost or another fertilizer type to the soil will encourage the plants to grow well and bloom quickly., Each hole should be about 4 inches (10.16 cm) deep.When digging the holes, leave enough space between the plants that growing dahlias will not choke one another or steal nutrients from one another.
For smaller varieties, leave 2 feet (0.61 m) between holes.
For medium or giant dahlias, leave 2 to 3 feet (0.61 to
0.91 m) between holes., Dahlias need plenty of fertilizer to grow successfully, and adding organic material to the soil ahead of time will help ensure that the plants grow well.
Scoop a small handful of compost and bone meal into each of the holes, and add a small scoop of dry fertilizer.You can purchase ground bone meal at a local plant nursery or gardening center.
If you do not already own compost and fertilizer, you can purchase them from a large gardening center or from a landscaping outlet. , Drop a single tuber in each hole, and then fill with soil.
You can expect to see the tubers growing in 2 or 3 weeks.Be sure the growing point of the tuber faces upward before you cover it with soil.
After each dahlia has been planted, water the soil lightly. , Do not water the dahlia tubers before you can see growth, or you’ll likely drown the plant.
Wait until you can see sprouts above the soil, and then water the dahlias only in the morning.
This will prevent the water from evaporating if you live in a hot zone.It’s not necessary to water the dahlias every day.
Keep an eye on the plants and, when they begin to look a little wilted, water them generously. , Fertilizers can help your dahlias grow quickly and well.
They’ll thrive if given a low-nitrogen liquid fertilizer, which is the type most commonly used for vegetable gardens.
You can fertilize the dahlias once they begin to sprout.
Continue by fertilizing the plants about once each month until August.You can purchase low-nitrogen liquid fertilizer at a local garden center or plant nursery.
It may even be available at a supermarket.
Look for a 5-10-10 or 10-20-20 mixture. , Tall dahlias may not be strong enough to support the weight of their own stems and flowers.
Prevent these plants from falling over by tying them to stakes shortly after they begin to grow.
You can use a thin piece of regular string or twine to fasten the stem to the stake.You can use a plain wooden stake or dowel to secure the dahlias.
If you’d rather have a more decorative garden, purchase a cylindrical tomato cage and let the dahlia use it as a support. , Once a dahlia plant begins to develop several bunches of bushy leaves, pinch off all of the flower buds, except for the bud at the very top of the plant.
This is known as the terminal bud and will produce a very large flower if the other buds are removed.If you’re not concerned with producing large, impressive flowers (of the type that would be entered in a flower competition), you don’t need to disbud the plant.
Simply let the buds grow where they will.
About the Author
Diane Flores
Experienced content creator specializing in crafts guides and tutorials.
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