When to Plant

Dahlias are planted in the spring when the ground temperature is approximately 60 degrees or warmer (exceptions will be hot climates); generally, when you would plant your vegetable garden. Planting times vary depending on your exact climate. For example, California, Hawaii, and Florida begin planting in March. The Southern half of the US usually begins planting in the middle of March. Oregon and Washington begin planting at the end of April, while the Northern half of the US begins in May. All areas usually finish planting by the first week of June.

Planting

Dahlias are ready to go in the ground when your ground temperature has reached 60 degrees or warmer. Be sure that your soil is workable and not soggy. The ground should be warm, well-drained at planting, and in an open sunny location.

If you have heavier soil, add sand, peat moss, or bagged steer or cow manure to lighten and loosen the soil texture for better drainage. Planting dahlias too early, in cold wet soil, may result in rotting tubers. Dig a hole 4-6” deep, lay the tuber horizontally (on its side), then cover it completely with soil. If the tuber sprout(s) is longer than 2 or 3" in length, it would be best to trim/pinch the sprout back to a length of 1”. This will not hurt your dahlias, in fact, this will help them have a stronger stalk by pushing through the soil. We recommend planting 12-24" apart. An average 4' dahlia plant will be 18"+ in diameter.

Bone meal is ideal at planting time. Add a small handful of bone meal to the hole and work it in well before planting the tuber. However, beware if you have pets or other animals around, they are attracted to bone meal and may dig up your tubers, we would recommend skipping this step.

This is the ideal time to put in your garden stakes. AT THIS POINT YOUR DAHLIAS DO NOT NEED MUCH WATER UNLESS YOU ARE GROWING IN CONTAINERS (See container growing instructions). Begin your watering regimen AFTER sprouts have appeared above the ground. There is an EXCEPTION in hot climates and/or container growing, where you will need to be sure the soil is slightly damp at planting as tubers do need a small amount of moisture to get growing. In hot climates, we recommend light watering once a week after planting until the sprout appears. Naturally, we assume Mother Nature will give us enough rain in the northern states at planting time, that additional water is not needed until you see the sprouts above ground. However, with changing climates, if your dahlias are planted in bone dry conditions and you aren’t receiving any rain for a few weeks, you will need to provide your dahlias with a little moisture to get started.

At this point do not cover your dahlia beds with bark dust or any other mulch as this will prevent the ground from warming up and allowing your dahlias to get growing. Snail and slug bait should be applied immediately in all climates.

Continue applying slug and snail bait throughout the season to protect them. The average time for dahlias to sprout through the ground is 3-5 weeks. If you have any dahlias purchased from us this season, that have failed to sprout through the ground after 5 weeks, dig them up and contact us immediately for assistance. Do not discard them, as photos of them will be required or return of the tubers may be requested.