How to Grow

***Note: Don’t be afraid of dahlias! Gardening is for joy...While they do take a bit of know-how

for best outcomes, dahlias are really no more difficult to grow than any other garden flower. In

milder climates, some gardeners choose to leave them in the ground and skip the fall dig and

dividing process. But, for most of us, the digging up, after they die off from frost, will be a part of

the experience. With a little know-how and effort, you can have a great cut flower garden from

late July/early August through Mid-October.

Planting:

Plant when ground temperature is approximately 60 degrees or warmer (exception will be hotter

climates). Here in the Pacific Northwest, the planting time is approximately May 1-15. That said,

the last couple of seasons have seen unusual weather patterns that are making planting dates

more of an estimate than ever. The main goal to keep in mind is to plant as early as possible but

not so early as to expose to cold and wet conditions that will rot your precious tubers.

Plant in an area that will receive full sun 6-8 hours per day. If temperatures are very hot in your

area, the plants will appreciate, and bloom stronger, with some late afternoon shading if

available. But they will survive without it. Soil should be well-drained. Raised beds are great for

dahlias. Ph is ideally slightly acidic (6.5-7.0)

Dig, and prepare, a hole (or trench if you are planting in a row) 4-6” deep. Here in our gardens,

we add a generous handful of bone meal and a fat pinch of magnesium sulfate (epsom salts)

in the trench at planting. The plants are very happy with this. You do not need to add additional

fertilizer at planting. This will come later.

If the visible eye/sprout is longer than 2-3”, it is okay. Just pinch it back to about 1”. If there is a

sprout, and it breaks off in transit, do not worry. Like the mythical Hydra, Where one sprout

head is cut off, many more will then grow in its place.

Lay the tuber horizontally on its side and cover completely.

Plant 12-24” apart. The average plant size will be about 4’ tall and 18” in diameter.

Unless it is extremely warm or you are growing in a container, do not water until there are plant

sprouts emerging. It will take 3-5 weeks for sprout emergence to occur.

Sluggo for slugs and snails is a must! It is non-toxic to pets and children and very effective for

protecting your tender sprouts. We apply it before sprouts emerge. We re-apply if there is heavy

rain and the sluggo pellets dissolve.

If you place stakes for future support, it is ideal to place them at planting so as not to disturb

growing roots later in the season. Most non-dwarf varieties of dahlias benefit from being staked.

It prevents them from blowing over in the wind or breaking tall fragile stems from the weight of

bodacious flower blooms.

Tubers & What to expect:

A package of dahlia tubers is not a very sexy box of goods. They are brown, sometimes a bit

wrinkly. They vary in size and shape, even among the same variety. Any healthy tuber with a

live eye, and enough starch storage (about a AA battery size or larger tuber) is able to grow a

new full sized plant. The size of the tuber does not determine the size of the plant. A tuber is

essentially a starchy root with enough fuel to get a new plant started from the included DNA

package. We plant broken and ugly tubers in our gardens and they grow as well as the better

looking ones we send to our customers. Pretty is as pretty does.

Your tubers will arrive in a box filled with pine shavings. They protect the tubers from cold and

rough handling during shipping. Each will come with a three digit number written upon it that will

match to the name of the tuber on the invoice. This is a system that saves us time during

processing.

Once plants emerge...

It is very important to keep nitrogen levels low. A fertilizer ratio of 5:10:10 is best for strong

blooms, strong tubers and good plant growth. Do not use a high nitrogen fertilizer or you will be

disappointed in the results. Avoid manures that have not mellowed as they will burn your plants.

Fertilizer should be applied approximately once per month to keep plants growing well. If your

soil is well amended with organic matter, less feeding may be necessary.

Once plants have emerged above the soil line, water deeply 3 times a week, allowing soil to dry

in between waterings.

When they have grown 3-5 sets of leaves, pinch the uppermost set back. This will delay flower

blooming a little bit but you will be rewarded with larger plants that ultimately give you many

more flowers.

Blooming Season:

This is the reward for all of your efforts!! Enjoy the flowers! Cutting or deadheading spent

blooms will cause the plants to bloom even more. Do not be afraid to cut your blooms.

Flowering will continue through the first hard frost. When hard frost arrives, your flower patch will

turn black and die back overnight. This is the end of the flowering season.

After Frost:

Allow plants to rest about 2 weeks after frost die back. This allows them to push eye

development in a way that will make them easier to see when dividing later.

Cut stocks down to about 6” to provide a “handle” when digging up.

The tubers will be in a circle about 12” in diameter and not too deeply down in the soil. A gentle

working along the edge with a pitchfork or other tined digger will help the bundle to pop out from

the ground.

Digging in dry weather will be much easier on the digger and help prevent rot development.

That said, weather does what it does. So, do your best with what arrives.

Dividing and Storage:

Once dug, tubers can be stored with soil left on them. If you want to wash them, wait about 24

hours as the tubers will “set” and less breakage of tuber necks will occur.

They must be stored in a cool dry place that is protected from freezing.

Storage temperature ideally is 40-50 degrees. A cellar or unheated enclosed garage works well.

Dividing dahlias has a bit of a learning curve. Each tuber must contain a body, a neck and an

eye to develop. Eyes appear like small bumps along a line at the edge of where the tuber

attaches to the main plant. If in doubt, leave clumps of tubers whole until Spring when the eyes

will begin to “pop” and be easy to see. Some gardeners simply take a clump and whack it into

4ths knowing that the odds are high that there will be adequate eyes located somewhere in the

section. With practice, dividing becomes much easier. (We sometimes offer a 1⁄2 day class for

this. See events section for updates on schedule).

There is much debate about how best to store divided tubers. Here at our gardens, we store in

vented containers with pine shavings in a cold cellar. It has worked well with minimal tuber loss

occurring.

***A note on tuber loss:

We can do everything as suggested above and, well, some tubers will not make it. It’s one of

those sad gardening facts of life.

Tuber rot can, and does occur, in storage. We calculate for about 5% loss in storage as a rule of

thumb. Plan for this. It is normal. Plants are real things with imperfections. Grow more, store

extras and enjoy them!