How and when to split dahlia tubers?
The best time to divide your Dahlia tubers is right after you have dug them up for overwintering storage, two weeks after the first frost of the season appeared. Some other Dahlia growers wait a little longer until (early) spring, just before planting. Dahlias may be left in the ground over the winter; however, dahlias are susceptible to rot and/or freeze. Dahlias are not hardy since they are a tuber (thin-skinned) and not a bulb. If you wish to move or transplant your dahlias to a new location, you may do so in the spring.Planting tubers the wrong way is another common mistake. To grow strong roots and healthy stems, dahlias need to be planted at the right depth and in the correct position,” says Vasylchyshyna. Simply place each tuber horizontally in a hole about 5 to 6 inches deep, with the small growth bud facing upward.As fall rolls in, it’s time for many of us to start digging up our dahlia tubers. Why? Because if they’re left in the ground in colder climates where the soil freezes, your tubers will turn to mush. If you’re in a warmer region, you might be lucky enough to leave them in the ground all year.Popular varieties/colors sell out fast, so be sure to order early, in late fall or early winter. Tubers can be planted as soon as all danger of frost has passed and the soil has warmed up. In my zone, 7b, I usually start planting dahlias in late April/early May, but I’ve also done plantings as late as mid-June.
Can you plant dahlias straight after dividing?
If you are in area where dahlias overwinter, they just need to heal ~24 hours. But if you live in an area where they don’t overwinter, you need to store them and wait until frost has passed. Dahlias are technically perennials, meaning they can live for many years. However, in the UK, they are often treated as annuals because they do not survive frost.What kind of pot is suitable for planting dahlias in pots? Take a big pot of at least 30 cm (12) and preferably of sturdy ceramic or terracotta. Make sure the pots are well-drained, if not make extra holes. Preferably add a small layer of gravel, hydro grains or shards on the bottom.If you space them too closely, they might not have enough room to grow and disease might plague your dahlias because of lack of airflow. Proper spacing allows enough airflow, allows you to give the plants proper support, and lets you use your space in the most efficient way possible.Don’t take dahlia cuttings too late in the season. We could theoretically take cuttings from late spring to late summer, so the window is very wide. As long as fresh new shoots are coming out of the tuber, we could turn them into new plants.
Can I save dahlia tubers for next year?
Now once your tubers are dug, you can choose to either: store your dahlia tubers as entire clumps (and divide in early spring) or you can divide right away and store the divided tubers individually. Neither one way is better than the other, it more depends on the time (and space) you have available. Simply cut the plants back to just above soil level and leave the tubers where they are. Your dahlias will start growing again in spring. In hardiness zone 7, dahlia tubers can survive winter outdoors if the soil is well drained and you cover the area with a thick layer of mulch for insulation.In most parts of the country, dahlia tubers need to be lifted from the ground, cleaned, labeled, and stored for the next season. Lift your tubers soon after the killing frost or any time after 120 days after planting. In warm climates, some growers leave their tubers in the ground and lift and divide in spring.Join us as we walk through dividing dahlia tubers! Here’s a quick guide: 𝗪𝗵𝗲𝗻 𝘁𝗼 𝗱𝗶𝗴: After the first frost or 120 days in the ground. Wait a week after the foliage dies to let those tubers develop next year’s sprouts. Gently dig 8-10 inches from the stem.The tubers of dahlias will tolerate a light frost, however, they will not survive a hard killing freeze. A killing frost or freeze occurs when temperatures are below 28 degrees for a duration of hours or days, whereas a light frost may only be a couple of hours of temperatures below 32 degrees.When to Plant Dahlia Tubers. Unlike other bulbs such as tulips, dahlias like warm soils so plant dahlia bulbs during the warmer and longer days of spring.
How many dahlia tubers should I plant together?
Dahlias in pots Take a large, well-drained pot and plant 1 tuber in it. With a pot larger than 50 cm, you can plant as many as 2 or 3 tubers in the pot. The low-growing varieties grow easiest in pots, the taller the plants are the larger pot they need to root well and the more care they require. Dahlias are vigorous plants and the stems can become overcrowded. You may wish to thin them out in June or July to improve the overall display: Aim to keep seven to ten sturdy stems per plant.As a general rule, you can expect Dahlias to bloom 12-16 weeks after planting. We planted on May 22, so that means we can expect the plants to bloom starting around August 22 through September 22. A few overachievers might surprise you in July, but don’t hold your breath! Dahlias do not perform well in hot weather.Let’s say everything is optimal for growing your Dahlias (never happens but let’s just pretend), you could estimate 10 blooms per plant as an average over the course of the entire growing season. Some varieties will have way more, and just pump out the blooms, and some will have way less.Dahlias grow best when they receive a consistent supply of water. Drip irrigation is ideal, as it directs moisture to the root zone while keeping the foliage dry. If you are hand-watering, it’s best to water deeply once or twice per week.
What happens if you don’t divide dahlias?
Home gardeners don’t need to lift and divide their plants each year although it is advisable to do so. If the drainage is good the rootstock will survive winter and regrow in spring. Each plant will produce a clump of new tubers which, undivided, will produce smaller plants with poorer quality blooms. Storage Considerations & When You Need to Divide If tubers are stored properly, there’s no rush—dahlia clumps can remain whole until just before planting. Some growers prefer to wait until spring to divide, ensuring tubers stay intact longer, which helps prevent excessive moisture loss.Popular varieties/colors sell out fast, so be sure to order early, in late fall or early winter. Tubers can be planted as soon as all danger of frost has passed and the soil has warmed up. In my zone, 7b, I usually start planting dahlias in late April/early May, but I’ve also done plantings as late as mid-June.The reason we tend to dig up dahlias and store them out of the soil over winter is to keep them dry and frost-free, and prevent them from rotting over winter, as both conditions can damage and often kill off tubers.The best time to divide your Dahlia tubers is right after you have dug them up for overwintering storage, two weeks after the first frost of the season appeared. Some other Dahlia growers wait a little longer until (early) spring, just before planting.