Storing Your Tubers
The best temperature range for long-term tuber storage is 40-50 degrees. DO NOT ALLOW THE TUBERS TO FREEZE, or they will rot. Tubers may be stored at slightly higher temperatures, particularly when it is nearly time to plant; the warmer temps will encourage the tubers to “wake up.”
If you need to store your tubers before planting, there are several common methods, including storing them in vermiculite or peet moss, or wrapped in plastic wrap. Your tubers will arrive wrapped in plastic, and should be kept that way until it is time to plant. If you need to re-wrap your tubers, several tubers may be wrapped together, but make sure no tuber is touching another (plastic wrap must separate all tubers).
If storing for a while, unwrap and check your tubers periodically for rot. It is fine if a tuber starts to sprout, but don’t let the sprout get too long and leggy before you plant the tuber. If this is happening, move the tuber to a cooler location.
Do not store wrapped tubers in an airtight container, as they need some exchange of air. A loosely closed bag or box is fine.
Planting Your Tubers
Planting Your Tubers
Exactly when you should plant your tubers depends on where you live and the climate conditions in that particular year. Tubers may be planted outside 2-3 weeks before the last frost, as it will take several weeks for sprouts to emerge. They may also be started in pots and transplanted to the garden later. If you are transplanting, you should wait to do so until all danger of frost has passed, and the ground is starting to warm up.
Plant tubers 4-5 inches below the surface, with the neck and eye of the tuber facing up and placed closest to where you will stake the plant (ideally just a couple inches from the stake). We recommend placing your stakes before planting, to ensure that you don’t damage the tuber when you put the stake in.
Plant your tuber in slightly moist soil, and don’t water it until a sprout emerges. Overwatering tubers before they have sprouted or developed roots will cause them to rot. Rain is fine, as long as the tuber is planted in well-draining soil. Once the sprout has emerged and the plant is actively growing, water deeply once per week, or as needed depending on your local conditions (less if you are getting regular rain and more if you have heat).
Space dahlias about 2 feet apart (can be anywhere from 18-36 inches) in a location where they will be in full sun, if possible.
The Growing Season
Caring for Your Dahlias
As mentioned above, dahlias should be staked to support the tender stems and heavy blooms. Place your stakes before planting to avoid damaging your tubers, and for easiest access. Once the plant is growing, tie it gently but securely to the stake every foot or so.
When your plant is 8-12 inches tall, consider “pinching” it. To pinch your dahlia, count up four levels of leaves, and cut the dahlia with clippers or pinch it with your fingers just above the fourth level. Though this may feel counter-intuitive, it will encourage more vigorous, lateral growth, ultimately giving you more blooms.
The best time to cut blooms is early in the morning (other times are ok if the temperatures are cool), when the bloom is about 3/4 open. As with pinching, cutting blooms (including “dead-heading” blooms that have gone by) will encourage more growth and more blooms.