Dahlias can make delightful addition to garden

Published Apr 15, 2018 at 9:00am

Dahlias are perennial in that their tubers will give rise to plants every year. But those tubers are not capable of surviving being frozen, and so must be dug up and stored each year. In the spring, tubers, which were stored in the fall are retrieved from storage and divided.

Each divided tuber must have an “eye” (similar to the eye on a potato) if it is going to grow into a new plant.

After the threat of a frost has passed (many gardeners plant their dahlias at the same time as they plant their tomatoes), those tubers are then planted, about six-inches deep, in loose, loamy soil in a place where the plant will get full sun.

It is important to place a stake in the ground alongside the tuber at the time of planting, in order to avoid damaging the tuber later. Once the plant emerges from the soil, deep watering will help it develop a strong plant and encourage the reproduction of new tubers for next year.

Once the plant begins to mature, it can be pinched back in order to encourage a more shrub-like shape. As it reaches its full height, it should be tied to the stake in order to prevent it from falling over, which it may very well do once it is heavy with blooms. Blooms can be cut for floral arrangements, and the plants will continue to produce flowers until a frost.

Once frost has killed the plant, it should be cut down, leaving at least a few inches of the stalk in order to keep track of where the tubers are. After a week or so of allowing the tubers to “rest”, they can be carefully dug up using a fork. Allow them to rest and dry outside for a few days (assuming that they are not allowed to freeze), and remove as much soil as you can.

Some dividing of the tubers can be done at this time. Then store them in a dry, cool, well-ventilated, and dark place, such as a basement or attached (but not heated) garage.

They should be covered with a material such as soil, sand, composted leaves, compost or similar material. Store them in a container that can breathe, so that the tubers do not rot. A cardboard box works well, but do not store them in plastic buckets.

Come back in the spring, and you should already find new growth on the tubers, which can help you to identify viable tubers for division. Divide tubers at this time and you are ready to plant a new year’s crop of Dahlias.

Dahlias come in a wide variety of types. They vary by color, size, and the arrangement of petals. These types include pompom, informal decorative, formal decorative, dinner plate, water lily, and so on.

Colors of dahlias are also extremely varied, from white and pale yellow to deep reds and fuchsias, with many types of dahlias combining colors. Dahlias come in so many types that you are sure to find one (or many!) to suit your garden and floral display needs!