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When do you plant dahlias


Dahlias: How to Plant, Grow, and Care for Dahlia Flowers

Dahlias are gorgeous flowers that bloom from midsummer through autumn. In colder regions, be sure to dig and store them after frost hits in the fall! Available in a rainbow of colors and a number of sizes, dahlias are a lovely flower to grow in any garden. Here’s how to care for them in yours! 

About Dahlias

Dahlia is a member of the Asteraceae family, which also includes the sunflower, daisy, chrysanthemum, zinnia, and, of course, aster.

Dahlias inspire awe and a good cheer. Growing vegetables? Put a row of dahlias on the border, where they will not shade your edibles. They make for lovely cut flowers.

Dahlias love moist, moderate climates. Though not well suited to extremely hot climates (such as southern Florida or Texas), dahlias brighten up any sunny garden with a growing season that’s at least 120 days long. 

The tubers are planted in the ground in late spring. They are considered a tender perennial in colder regions of North America. They are reliably winter hardy in hardiness zones 8 to 11, although gardeners in zones 6 and 7 may have luck keeping them in the ground as well. In colder zones, dahlias can either be treated as annuals or dug up after the first frost and stored indoors for winter. (See what hardiness zone you’re in!)

Picking a favorite dahlia is like going through a button box. In addition to coming in a rainbow of colors, dahlia flowers can range in size from petite 2-inch lollipop-style pompoms to giant 15-inch “dinner plate” blooms. Most varieties grow 4 to 5 feet tall.

Harvesting

Dahlias as Cut Flowers

The more you cut dahlias, the more they’ll bloom—and dahlias are beautiful in a vase. For a bouquet, cut stems in the morning before the heat of the day and put them into a bucket of cool water. Remove stems’ bottom leaves and place the flowers into a vase of water. Place the vase in a cool spot and out of direct sun. Check the water daily. The bouquet should last about a week.

Digging and Storing Dahlias for Winter

Unless you live in a warmer region (USDA Hardiness Zone 8 or warmer), you’ll have to dig up dahlias in late fall. Native to Mexico, Dahlias won’t survive freezing temperatures. Digging and storing dahlias is extremely easy and simple, and will save you the money that would otherwise go into buying new ones each year.

→ Find your USDA Hardiness Zone here.

How to Store Dahlias in Winter

Tuber clumps can either be left intact for the winter and divided in the spring, or they can be divided in the fall. Some gardeners find that it is easier to divide in the fall, and divisions are more convenient to store. 

Check on the dahlia tubers occasionally over the winter. Remove any tubers that have started to rot before the decay spreads to healthy tubers.

Readying for Summer

In spring, separate healthy tubers from the parent clump and discard wrinkled or rotten ones. Plan to plant the survivors.

Each tuber must have at least one “eye” or piece of the crown attached or it will not develop into a blooming plant. The eyes are little pink bumps at the base of the stem.

→ See our gardener’s article on how to unpack and divide your stored dahlia tubers!

If this all seems like too much bother or you do not have the right storage place, skip digging and storing, and just start over by buying new tubers in the spring.

for bold blooms and beautiful cut flowers |

(Image credit: Getty Images)

They bloom from mid-summer to late fall, but you might be asking when to plant dahlias to enjoy their extravagant display. 

Growing dahlias extends the season with big, bold flowers that fill the backyard with color. Most are tall, adding height at the back of the border, and the single-flowered cultivars provide nectar for bees and butterflies. On top of that, dahlias have a cut-and-come-again habit, so they supply beautiful, fresh flowers for the house.  

Our guide has the details on when to plant dahlia to get the most from these colorful, exotic flowers. 

(Image credit: Getty Images)

When to plant dahlias

Hailing from Central America, dahlias shouldn’t be planted outside until the weather warms. If you have stored or bought tubers the answer to when to plant dahlia tubers is to pot them up under cover (for example, in a greenhouse) in March or April. Rooted dahlia cuttings are also best started off under cover in mid to late spring. And potted dahlias should go in the ground after risk of frost has passed, which is May or June in most regions. 

Dahlias are available in such a vast range of colors and shapes that you can select the ones that best suit your style of garden. For instance, the cactus and ball varieties bring retro glamour; the single and anemone forms fit into jungle-style flower bed ideas; and the huge dinner-plate dahlias are a must-have for a cutting garden.  

‘I like to intersperse dahlias among other plants,’ says Oregon-based landscape architect and garden designer Bethany Rydmark . ‘For example, dahlias work well in modern meadows, as accents in a mixed border, or as infill in a parterre.’

When to plant dahlia tubers indoors

Dahlia tubers that you have stored over winter or bought can be potted up under cover (for example, in a greenhouse) in March or April, and then planted outside in May or June. 

‘Planting tubers will often give you earlier flowers,’ say Dave and Sue Hall at specialist dahlia nursery Halls of Heddon , near Newcastle upon Tyne, UK, ‘because more often than not they will produce multiple shoots which will not need pinching out.’ 

It is best to harden off the young plants to acclimatize them to outdoor conditions before planting. For example, by placing them in a cold frame or by sitting them outdoors during the day for a week covered with fleece, then gradually remove the fleece.

When to plant dahlia tubers outdoors

What about when to plant dahlia tubers outdoors? ‘Dahlia tubers can be safely planted out between April and May,’ say Dave and Sue Hall. ‘The warmer the climate, the earlier you can plant. So the further south you live in the UK, the earlier you can plant.’ 

In most parts of the UK and the northern US, it is safe to plant dahlia tubers direct outside from mid to late April. 

Usually, the tubers will set about growing their roots during late spring and begin sending up new shoots in early summer. However, sometimes they may shoot early in warm spring weather. Don’t worry because this won’t damage the plant in the long run. 

‘Growth that emerges too early may be nipped back by spring frosts,’ say Dave and Sue. ‘The plants will recover and it should result in bushier plants earlier on, as they will have had a natural pinch.’ 

When to plant rooted dahlia cuttings

Mini plants, known as ‘rooted cuttings’, are readily available from dahlia suppliers in mid to late spring. They are often more reliable than tubers in establishing robust plants faster and can produce a better flower color. 

If possible, plant them up under cover (for example, in a greenhouse) during spring. ‘Dahlia rooted cuttings can be planted directly outside, but they will certainly benefit from being potted up and grown on for at least a few weeks before planting out,’ say Dave and Sue Hall. ‘In the south of the UK, planting out can be done from early to mid May. In the north and Scotland, you would not normally plant out until June. We would not advise planting out before the date of the last expected frost in your area.’ 

Harden off the young plants before planting out, in order to prepare them for the weather outside. For example, by placing them in a cold frame or by sitting them outdoors during the day for a week covered with fleece, then gradually remove the fleece. 

When to plant potted dahlias

In late spring and early summer, ready-grown dahlias in pots can be bought from nurseries. As for when to plant dahlia like these? They can be put directly into sunny borders once all risk of frost has passed. 

‘Only buy fresh, strongly growing plants that have not become pot bound,’ advise Dave and Sue Hall. ‘Being pot bound will put a check on their growth and they will be slower to get away.’ 

To check if a plant is pot bound, peer underneath to see what the roots look like. If they are old and in a dense knot under the plastic container or – if you are able to slide the plant out of its container – should they be growing around and around the compost, avoid purchase.

When to plant dahlias in pots

If you want to grow dahlias in pots to brighten up the patio or terrace, plant the tubers into well-drained containers of peat-free compost under cover (for example, in a greenhouse) in March or April. Then, once risk of frost has passed, move the pots outside into a sunny position. 

‘Totally Tangerine’ (orange), ‘Red Fox’ (scarlet), and ‘Verrone’s Obsidian’ (claret) all reach around 2.5ft (75cm), making them ideal for containers. Water dahlias in pots regularly, as they like moist compost. 

When to sow dahlia seed

Dahlias are usually grown from tubers, which is far easier and quicker. However, if you like a challenge, they can also be raised from seed. Sow the seed under cover (for example, in a greenhouse or on a bright windowsill) in early spring. Once they are large enough, harden off the young plants and then plant into borders in June. 

When should I start my dahlia tubers?

Start dahlia tubers in March or April by potting them up under cover; plant them outside in May or June. If you don’t have space to start them in a greenhouse or indoors, dormant tubers can be planted directly outdoors between April and May.

How late can you plant dahlia tubers?

You can plant dahlia tubers as late as May or June in most regions. When it comes to their blooming season, they should carry on up until frost.  

Lucy Searle has written about interiors, property and gardens since 1990, working her way around the interiors departments of women's magazines before switching to interiors-only titles in the mid-nineties. She was Associate Editor on Ideal Home, and Launch Editor of 4Homes magazine, before moving into digital in 2007, launching Channel 4's flagship website, Channel4. com/4homes. In 2018, Lucy took on the role of Global Editor in Chief for Realhomes.com, taking the site from a small magazine add-on to a global success. She was asked to repeat that success at Homes & Gardens, where she has also taken on the editorship of the magazine. 

When and how to plant dahlia tubers outdoors

If the rose is considered the "Queen" of flowers in many countries, then the dahlia is without a doubt their "King". Very few ornamental plants can boast such a wealth of shapes, sizes and colors!

In addition, the dahlia is very unpretentious. Content with the most minimal care, he pleases the gardener with his bright, lush flowering from early July until late autumn.

About the history of the appearance of the dahlia, how to care for it, how to dig it up and store it in the winter, we have already told in our article: "How to grow dahlias".

In this article we will tell you when and how to plant dahlias in spring. In addition, we will tell you the best varieties of the numerous species of this regal flower.

COMMON TYPES OF DAHALHINS FOR THE NORTHERN AND CENTRAL REGIONS

The timing of planting and preparation of dahlia tubers depend on their type. Most often, Russian gardeners choose the following:

Large-flowered. In height they grow up to 80 cm, and the diameter of the flowers of the newest varieties can reach 30 cm!

Decorative . These are large bushes up to 1 m high with numerous flowers up to 25 cm in diameter. This species is distinguished by the richest palette of colors and variety of forms.

Cactus . The tallest bushes - can grow up to 1.5 m. Flowers with a diameter of up to 20 cm are distinguished by the most bizarre shapes and unusual colors.

Pompoms . Plant height - 80 - 90 cm, diameter of flowers - up to 15 cm. Flowers of bright, saturated colors look like mesh balls. They look very beautiful and last a long time in a vase after cutting.

Semi-cactus . Tall, sprawling bushes (up to 1.2 m) are covered with holly, bright flowers, up to 18 cm in diameter and a variety of one-, two- and three-color colors.

Miniature . The most elegant dahlias, up to 40 cm high, are literally strewn with large flowers, up to 15 cm in diameter. They bloom earlier than others and do not crumble during the first winter frosts.

WHEN TO PLANT DAHALAHS

Planting time for dahlias depends on the region where you live. The main condition is that the earth should warm up well, because the plant is a tuberous plant.

In the Middle lane, North-West region, dahlias are planted in the third decade of May. If the spring turned out to be early and warm, then it can be a week earlier. However, when return frosts appear, a flower bed with dahlias should be covered with a non-woven covering material.

If you come to the dacha only on weekends, then it is better to move the planting date to June 25-27. After May 25, spring frosts usually stop.

In the Urals and Siberia, the spring is later and more humid. Therefore, dahlias are planted there in late June - early July. And it’s better to first germinate them in a pot, and plant the seedlings in a permanent place after July 10.

In the southern regions of the country, dahlias are usually planted in April, as the land there quickly dries up and loses moisture. Therefore, it is impossible to be late with the deadlines.

All varieties of dahlias that tolerate cold climates will grow well in the south. This is a versatile and very unpretentious flower.

HOW TO PLANT DAHAHINAS FOR EARLY FLOWERING

If you bought tubers in March-April, you can germinate them in advance and get early lush blooms. To do this, fill some kind of container (box or basin) with a wet substrate, consisting of purchased soil for seedlings of flowers, sand and sawdust in equal amounts.

Make drainage holes in the container to drain excess water and build some kind of drip tray.

Wet the substrate well and place the dahlia tubers in it, sprinkling them with a 10 cm layer of soil. Place the container in a warm place and cover with a transparent film on top.

Very soon the plants will grow. After the first shoots appear, move the box to the window. Water your plants regularly. At the end of May, transplant them into a flower bed.

This planting of germinated dahlias will ensure that they bloom 2 to 3 weeks earlier.

PREPARATION OF DAHALH TUBES FOR SPRING PLANTING

All gardeners know how to plant dahlias, but not everyone correctly understands how to prepare them for this operation.

Before planting, we recommend treating even healthy tubers in three different solutions, dropping them there sequentially and holding for 30 minutes.

First, treat the dahlias with a pink solution of potassium permanganate, then with Fitosporin M, and finally, dip them into the Zircon solution.

The first two preparations will disinfect the tubers from any bacteria and pathogens of fungal diseases. The third - will accelerate the process of germination of sprouts on the tuber.

Then place the tubers on a dry, clean cloth or paper and let dry. After that, you can start landing.

HOW TO PLANT DAHALAHS CORRECTLY

Dahlias like quiet, sunny places with light shade during the midday hours, well protected from wind and drafts. But if the plants are exposed to the sun less than 6 hours a day, then they may not form buds.

Dahlias prefer loose, fertile soils with a neutral reaction. It is better to choose “native” soil from the planting pits and fill them with a soil mixture composed of a fertile layer, compost, sand and leafy soil.

In each hole, add phosphorus-potassium fertilizer, wood ash (1 bucket for 4 plants) and a glass of dolomite flour (on acidic soils).

Dig planting holes with a depth equal to the diameter of the bulb plus 10 cm. Of these, 5 cm is a drainage layer of coarse sand or perlite, which is laid on the bottom of the hole.

Distances between plants depend on the species and variety. Low-growing dahlias are planted at a distance of 40 cm from each other, tall ones - 70 cm.

Mulch the flower bed well with sawdust or freshly cut grass. The mulch will retain moisture in the soil and discourage weed growth.

For more information on how to care for dahlias, when and how to dig them up and store them, see our aforementioned article "How to Grow Dahlias".

THE BEST DAHELHIN VARIETIES FROM OUR COLLECTION

Now that we have told you in detail when and how to plant dahlias, it remains to choose the most beautiful types and varieties. We can help you with this.

We offer you the best and most popular varieties of dahlias from our collection.

LARGEFLOWERS:

Latest: Avignon, Sir Alf Ramsey, Arthur Humbley, Almond Joy, Big Brother.

Our collection: Vancouver, Flood Light, Sensation by Otto, Fleur, Spartacus.

DECORATIVE: Passionate, Mero Constellation, Gypsy Girl, Tartan, Cream Peach.

POMPON: Sunny boy, Lipoma.

CACTUS: Freequolet, Aloha, Silent Folly.

SEMI-CACTUS: Firebird, Favorite, Kennemer.

MINIATURE: Salvador, Pablo, Riviera.

You can buy all these dahlias from us right now. We have no doubt that they will bring you many pleasant moments and decorate your garden in an unusual way!

Growing dahlias from tubers is a fairly simple and affordable process for every grower, so even beginners do not have to worry, as can be seen in the video below. It provides simple and understandable information for everyone, so that anyone can please themselves and loved ones with beautiful lush flowers in the middle and end of summer, when other plants can no longer boast of such lush and abundant flowering.

Spring has come, we are increasingly thinking about what to plant in the flower beds. Many have already taken dahlias out of the cellars and placed them for germination. We talked in detail about how to do this in one of the articles and we hope that you have no problems. Planting dahlias with tubers in the spring is also not particularly difficult.

A little about dahlias

Did you know that the dahlia came to Europe as an edible, not an ornamental plant? Only now the capricious Europeans did not appreciate its taste, but they quite liked the flowers, they began to grow them in front gardens. Then breeders took up the dahlia. As a result, we have more than 15,000 varieties, the number of which is increasing every year.

The root system of a dahlia is root cones or root tubers, which are a thickened modified root, not a stem like a tuber. A flower and not a flower at all, but a complex inflorescence - a basket consisting of many marginal reed flowers and internal tubular ones. The trunk of a dahlia is hollow, but very strong. With the current varietal diversity, the growth of this flower can vary from 20 to 150 cm and more, and the diameter of the inflorescence - from 3 to 25 cm.

Dahlias are flowers with an annual cycle of development and a pronounced dormant period. Starting from spring, they grow, bloom, after the first frosts, their vegetative mass dies off, and the tubers go to rest. A few months later, they wake up after winter, in the spring the root collar releases the first shoots and everything starts all over again. It should be noted that dahlias are very thermophilic and do not winter on the street.

Preparing dahlias for planting

In one of the previous articles on our site, we described in detail the germination of dahlias in the spring, but let's repeat the main stages of this process.

We get root tubers from storage

We will assume that our tubers were stored correctly, and wintering was successful. The timing of when to get dahlias from storage in the spring is different for each region. This should be done about 2-3 weeks before landing in the ground. Usually for central Russia this is mid-April. If you plan to propagate flowers from cuttings, do so at least a month in advance. It is impossible to get the tubers out of the basement in the spring and immediately bring them into a warm room, due to a sharp temperature drop, you can simply lose the plant.

Attention! First, put the boxes in a cool dressing room, carefully cover them with cellophane to retain moisture and leave for 2-3 days.

Only then can dahlias be brought home.

Preparation and disinfection before sprouting

Any preparation of dahlias for planting begins with the disinfection of tubers. If after digging you have not washed them from the soil, it's time to do it in the spring. Carefully inspect the washed tubers for possible rotting, mold and infections. Remove all affected parts with a sharp sterile knife and soak the tubers in a pre-prepared slightly pink solution of potassium permanganate for 30 minutes. Then sprinkle all sections with crushed activated charcoal and leave for a day to dry.

Germination of dahlias

Germination of dahlia tubers in spring can take place in any loose substrate:

Sprinkle some damp substrate on the bottom of the boxes and carefully place the tuber nests on top. Most importantly, the root neck should be directed upwards, it is on it that the growth buds are located. Lightly sprinkle the tubers with soil and place in a bright place with a temperature of about 20 degrees. When the first shoots appear, lower the temperature to 15-16 degrees.

Important! Dahlias should not be cramped in sprouting containers.

If you have few nodules, you can germinate them in pots without deepening the root collar.

Tuber division

It is not necessary to divide dahlia tubers every spring. But if you neglect this procedure for 3-4 years and plant only large overgrown nests in the ground, the flowers will gradually degenerate. The absence of spring division of dahlias is fraught not only with the fact that you miss a rotten tuber, which, after planting, will provoke decay of the entire root system, but also with the appearance of small few flowers.

When the first sprouts appeared or just the growth buds swelled well, it was time to divide the tubers. This must be done on time, not allowing the shoots to become large - so there is a danger that during the division we will simply break them off, because in the spring, at the initial stages of growth, they are very fragile.

We invite you to watch a video in which an experienced gardener talks about the division of dahlia tubers:

After you have divided the tubers and dried the sections, return them to the sprouting boxes.

Cuttings of dahlias

Dahlias are planted in spring not only with tubers. This plant is easy to propagate from cuttings. When the young shoots reach a height of 6-10 cm, they are carefully broken out with a “heel” or cut out with a sharp sterile knife with a piece of the root neck and planted in separate pots or peat tablets.

Attention! Cutting dahlias in the spring allows you to grow many plants at once from one nest, which is especially important if the flowers are grown for cutting.

This is how the rejuvenation of planting material takes place.

Care of dahlias during germination

In the spring, during germination, do not get carried away with watering - the tubers have a sufficient supply of moisture and nutrients for the first time. Here it is better to dry the soil a little than to over-moisten it. It is better to carefully spray the seedlings with a spray bottle.

After you have divided the dahlia tubers, you will have to make sure that there are not too many shoots on each division. It's not a pity, leave 2-3 of the strongest, and break out the rest.

Warning! If you leave a lot of shoots in the spring, the plant will be weak, and the flowers will be small and few, and you will not get good tubers by winter.

Planting dahlias outdoors

We have shown how to prepare dahlias for planting. Believe me, this is not a difficult matter, you just need to get used to it a little and find a suitable place for germination, because if there are a lot of tubers, then they need a lot of space, and even well-lit. Now it's the turn to describe how to plant dahlias in the spring.

Planting Site Selection

Dahlias need plenty of sun, shelter from high winds, and loose, moderately fertile soil. These flowers are surprisingly unpretentious to the soil, you can not plant dahlias only in a wetland - there their tubers will simply rot.

Preparing the planting site

The best way to prepare the site for planting flowers in the fall is by digging the bed with a shovel bayonet. Although dahlias can be grown in any soil, it is better not to create extreme conditions. Add lime or dolomite flour to too acidic soil, and acid (moor) peat to alkaline soil. If your soil is poor, add mature compost or well-rotted humus.

In spring, the soil is dug up again.

Planting dahlias in the ground

The time when to plant dahlias in the spring in the open ground is different in each region. It must be remembered that these flowers are very thermophilic and even a short-term decrease in temperature will cause their death.

In the spring we plant dahlias in the flowerbeds, not only when the threat of return frosts has passed, but also when the earth warms up well. The hole needs to be dug approximately on the bayonet of a shovel, add a matchbox of superphosphate, mix well with the soil. If the soil is poor in nutrients, we additionally add well-rotted humus or a complete complex fertilizer, for example, amophoska. In excessively dense soil, add peat or sand.

In case of dense soils, we will arrange drainage - we will put a shovel of fine gravel or brick chips on the bottom of the planting hole.

Attention! If your soil is light and loose in itself, do not make additional drainage, otherwise the dahlias will have to be watered every day!

Place the tubers in the planting hole, cover with soil so that the root collar is about 2-3 centimeters deep.

Tip! There is such a rule: the hole should be three times larger than the tuber nest, and add about 7 cm to its depth to add humus and deepen the root neck.

Be sure to support tall varieties in the spring before planting, you risk damaging the tubers if you do this later. After the plant is planted, water it generously.

Planting dahlias in containers

Planting low-growing varieties of dahlias in containers is now very popular. City residents who grow flowers on balconies and loggias can also grow them. It is important to remember one thing - flower pots are only suitable for dahlias grown from seeds. In the spring, a stalk of a low-growing variety can also be planted in a pot, but its volume should not be less than 5 liters.

Dahlia tubers are planted either in large ceramic flowerpots or in containers with a volume of at least 15 liters, but this is a minimum, and for the smallest flowers with a small tuber! Usually containers for planting dahlias have a volume of 30-40 liters. Otherwise, the plant will suffer from a lack of soil throughout the season and will give a weak nodule, which will most likely die in winter.

Important! Container dahlias require increased watering, mandatory holes in the bottom of the pot and a good layer of drainage so that water does not stagnate at the tubers and cause the death of the flower.

Care after planting

The first time after planting, dahlias need intensive watering and protection from the bright sun. You can just cover the plants with newspapers for the first 2-3 days. These flowers do not like loosening, since we do not know where the growth of new tubers will be directed and risk damaging them.

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