Dahlia tubers come in all shapes and sizes. With the right growing conditions, they will grow into healthy plants with gorgeous blooms.

Storing

I pot up each tuber as they arrive. I add a bit of steer manure, bone meal, water and then keep warm.

If you have received your tubers prior to your last frost date, you can do one of two things. 1) Pot them up temporarily in quart size pots (or larger, please read “planting” below) until weather is warm enough to plant outside (please read below). Start with moist soil (not soggy) and water when soil begins to dry out. As per below, tubers will rot if overwatered (or if frozen). Store where there is no chance of freezing and where they will get sunlight once they have sprouted above the soil surface. OR, 2) Store them in a container filled with your preferred material (dry peat moss, vermiculite, etc.) in a dark, cool space (40 - 50°F and 80 - 90% humidity) until soil temps have reached 60°F or higher. Check tubers often until planting.

Sun

Dahlias require full sun (at least 8 hours per day). Some shading may be required during extreme heat.

Planting

Choose an area with well draining soil (amend if needed, but only with soil or compost that has not been treated with fertilizer or chemicals). Soil should be moist but not soggy at time of planting. Dig a hole 4 - 6” deep, add a small handful of bone meal and steer manure (both optional), mix with the soil then lay the tuber horizontally on its side, eye-side up, and cover.

Support

Most dahlias benefit from support, and the best time to add it is at planting. Doing so now will prevent you from accidentally piercing the growing tuber clump at a later time. Labelling your stake helps keep track of which variety is planted where.

Watering

Once planted, do not water until it sprouts above ground. It can be very tempting to do so, but excessive watering can lead to tuber rot. Unless you are experiencing a very hot period of weather, they should be fine. On the other hand, should an epic rain event be on the horizon, laying a tarp over planting site couldn’t hurt. Once they have sprouted above ground, begin watering your dahlias on a regular basis (the schedule of which will depend on your rainfall, temperature and soil conditions). The one true thing about watering dahlias is that long, deep waterings are 100% necessary. Hand watering is not enough for dahlias, they need long soaks via sprinkler or soaker hose. This could be daily or weekly.

Fertilizer

Dahlias require a low nitrogen fertilizer, typically referred to as “bloom” food/fertilizer. Look for a fertilizer where the first number is 1/2 of the other two numbers. Start your first feeding 30 days after planting, then repeat once a month through the growing season. Just as plants need more water during an extreme heat wave, they will need more food as the stress will cause them to use it up faster.

Pinching

For bushier plants, pinch or cut the center shoot of your new plant just above the third set of leaves (or when the plant is roughly 18-20” high). This is just a one-time pinch to help promote stronger stems and more branching.

Overwintering

Before the first frost in your area comes, know whether you can leave your dahlia tubers in the ground or if they need to be lifted and stored overwinter. There are many methods and mediums for storing dahlia tubers, simply Google “Overwintering Dahlia Tubers” to see what other dahlia growers are doing, pick one or more methods to see what works best for your storing area.

This is just the tip of the iceberg of how to care for your dahlias. Please read all of the info out there, try different techniques for storing, watering, feeding, etc. You will find the happy place that works best for you and your dahlias.

Feel free to email with questions, I’m happy to help as best as I can!

It’s Dahlia Time