Growing Dahlias

Spacing

Dahlias prefer space. Ideally 24”-36” between plants, however you can push them closer at 12” apart depending on your growing conditions. The closer the dahlia, the more you will need to tend to crowded plants and airflow. Dahlias need a sunny space to grow.

Planting

Dig a hole 4” in the ground big enough for your tuber to lay horizontally. Amend planting hole with fertilizer*. Our soil is very high in potassium and phosphorus. All we add the the planting hole is a small amount of alfalfa or bone meal. Cover your dahlia and wait. There is no need for watering at this time, especially in the PNW.

*Before planting I recommend getting a soil test to accurately identify the your unique growing conditions and how to best support your dahlias.

Staking

Dahlias have a tendency to be top heavy and fall over. If your garden is effected by wind you may consider staking your plant. Stake at the time of planting so you do not harm your tuber later in the season. You can stake each individual plant or corral a row of them together with corner posts and twine.

Watering

Begin watering your plant when you have several inches of growth above the soil surface. Our watering schedules are based on the needs of our sandy soil and mild Pacific Northwest weather.

We have dahlias growing in two separate spaces, each receives a different watering schedule. All of our watering is at the soil surface, bottom watering, using 5/8” t-tape with 8” spacing between emitters. We have two lines of t-tape about one foot apart, per three foot wide garden.

House: At the house where we have our hybridizing projects our gardens are on professional t-tape. This space is roughly 1000 sq feet of garden. These gardens receive water for four hours every four to five days.

Field: Our other dahlias are in a field separate from our home. These dahlias are also watered with professional t-tape. This spans across a half acre, roughly 10,000 sq ft of planting space. These gardens are separated into four different zones that each get watered separately. Each zone receives 20 minutes of water, twice daily, every day.