Dahlia Care & Growth

Thank you for ordering Dahlias! The tubers are where the magic is kept, admittedly a bit wonky looking. The tuber you received should be true to the parent type you ordered. I have done my very best with labeling and keeping track but mistakes can and will happen, although rare. 

Please look over your tuber and you might find that the tuber has already began to sprout. Thats normal! You can snip it off it the sprout looks thin or spindly and the tuber will gladly grow another given the chance. Depending on your zone you may plant them out right away into the prepared soil or put them in storage until ready to plant out. 

DO NOT PLANT UNTIL THE DANGER OF FROST HAS PASSED

Soil preparation is one of the most important steps when growing dahlias. It's important they are grown in a sunny site with some shelter from wind if possible. 

Most Dahlia varieties benefit from some sort of staking or netting. It's up to you how to proceed. Larger blooms will break main stems if not given proper support. 

Soil should be amended with well rotted manure or compost, blood meal and bone if possible. Soil must be well draining. You will lose your Dahlia quickly if grown in sitting water. 

Dahlias should be planted 2-3 inches below the soil level and 12-18 inches apart. Do not water just planted tubers. The moisture that is naturally occurring in the soil will be enough to support the tuber until growth begins. 

At the time of planting, I insert a metal garden stake 4-6 ft tall depending on the variety planted. I also secure a label to the stake and in the ground. While both is not necessary, it can act as a form on backup if one happens to get lost. 

It is imperative that you understand what pests are in your area. Perhaps slugs, aphids, earwigs, grasshoppers etc. There are many options available to combat these pests. Aphids in particular are troublesome so its good policy to treat the leaves and stem preventatively instead of after infestation. 

To encourage more blooms on your Dahlia I recommend "stopping" or removing the growing tip at these intervals:

Large & Giant: stopped at 4 pairs of leaves

Mediums: 4 to 6 pairs of leaves

Smalls, Poms and Miniatures: 6 to 8 pairs of leaves 

Note: This is a general guideline and not mandatory 

Once mid summer has hit in July your Dahlias will be growing rapidly. Take care to tie in new growth and deeply soaking the soil to a 6 in depth. Watering at the soil level is more beneficial than overhead watering. I do not water overhead once the plants start to get quite large. Powdery Mildew will become a issue quickly so it's best to keep leaves dry when the weather is very humid. 

It's highly recommended to to apply a top dressing of a balanced 4-4-4 fertilizer at the 5 week mark after planting. I like Liquid Seaweed from Harvest Neptune. There are plenty of options. Once the Dahlias have had their first flush of blooms I will begin to apply bi-weekly feeds of  MaxSea Bloom Plant Food. 

I discontinue this in the month of September to allow for the tubers to grow and not focus as heavily on blooms. This is not necessary, just my personal preference. 

Deadheading regularly will also allow the Dahlias to focus on creating new buds and blooms. Once there is a bud it's good practice to disband the tiny side buds you see next to each main bud, often called "wing buds". It's very easy to pinch or snip them off. Be careful not to remove the main bud! It happens.. trust me.. 

If you would like to cut blooms to bring indoors or used in arrangements it's best to cut early morning or late evening. A sloping cut should be made and immediately placed into a cold container of water. 

Dahlias come in thousands of varieties, I believe that's what is so alluring about them. Each bloom is different from so many factors. Dahlias can be very exciting and very rewarding. They will continue to bloom until the first killing frost. 

Lifting and storing tubers is another topic entirely so I will create a section for that topic over the summer on how I personally handle the lifting/dividing/storage. 

ENJOY YOUR DAHLIAS!