The most important thing is to start with firm solid tubers. They should not be wrinkled or contain any soft brown areas which are the beginning of rot.
While not required to maintain the best quality of plants it is recommended that you divide the large clump of tubers from the plants that you have dug up and stored from last year.
If you have not done so already prior to storing over the winter you will want to divide the tuber cluster such that there is one or two tubers attached to a portion of the old stem of the plant.
This location where the stem joins the tubler is the area where the “eye” or buds are that form the new growth
These will grow into the stems of the plant for the coming year
Before you plant the tubers, you want to prepare the location where the plants will grow for the season.
They will need full sun and a well-drained soil that has been amended with composted cow manure.
Remove any weeds from the bed.where you will be planting your tubers.
I will identify what to do with the black cloth on the left side of bed later.
Cover the bed or location you are planting the Dahlia with composted cow manure. You do not want to use any amendment that is high in nitrogen as this will reduce the number of blooms on your plant.
I like to add about two inches over the surface of the bed where I will be planting mu tubers.
Next you want to turn the compost into the soil of the bed. Work the soil deeply the full depth of your pitchfork or spade. This will get the compost down around the roots to provide nutriments and improve the texture of the soil by improving water retention and improving drainage of excess water from the roots.
Smooth the surface of the bed by breaking up any clumps of soil and raking it smooth.
I then cover the bed with a black plastic mulch that has holes in it for where I will plant the tubers.
The black plastic helps warm the soil in the spring and as the plants grow helps control the weeds.
To hold the plastic in place you can use wire hold downs
or you can cover the edges with soil to hold the plastic mulch in place
At each location you place a tuber you will want to add a stake prior to planting the tuber
They will help support the plants if they are the taller growing variety. For the more compact and small varieties of dahlias you do not need to stake them
With the bed prepared and the weed blocker covering it
Place a support stake support stakes in place you are now ready to plant your bulbs
You will plant your bulbs with the stem/eye side up about three to four inches deep.
Shallower is better than too deep. You are looking to cover the tuber with q inch or two of soil.
DO NOT water the bulbs unless the soil is completely dry. If you can compress your soil in you hand and it holds together at all and does not drop thru your fingers there is enough moisture to get the bulbs started. Too much moisture at this stage of planting can cause the bulbs to rot in the ground.
Once the tuber is covered you will want to protect the new growth that forms from slug and snail damage. They love to dine on new dahlia growth.
Spread some slug and snail killer to keep them from eating your new growth and killing the plants.
Spread it around the surface of the soil in the planting hole and maintain it until the growth of your plant reaches a couple of inches in height.
Once the plant grows such that it has 3 or 4 sets of leaves it should be safe from the ravages of slugs or snails looking to make it a snack but you can continue treating to be safe.
Now that the plant is growing you can begin to waer it as needed. Do not apply a high nitrogen fertilizer ( has a number in the first postion of 2-10-10 higher than 5 and preferably lower. The application of nitrogen will result in lots of growth in the stems and leaves but inhibit the formation of the flowers which is why you are gorwing these after all.
I will continue with growing guidance and hints as the plants mature showing how to pinch the plants to increase flower production, how to suport the plants as they grow and how to harvest the flowers for bringing indoors to enjoy.