Growing Guide

Growing Dahlias in the North: A Guide for Short Seasons

Growing dahlias in a northern climate is a rewarding challenge. Because our growing season is shorter than in the south, we have to be strategic to get the most blooms possible.

There are two ways to start your dahlias. You can give them a head start indoors to get blooms earlier, or you can keep it simple and plant directly in the garden.

Here is how to choose the right method for you.

Option 1: Starting Indoors (The Head Start)
Best for: Gardeners who want blooms as early as possible (July) and have space for pots/grow lights.

In our short season, waiting to plant outside often means blooms don't arrive until late August. Starting indoors buys you an extra 4–6 weeks of growth!

 * Timing: Start your tubers indoors 4–6 weeks before your last expected frost date.

 * Pot Up: Use a nursery pot (1 gallon is great) with slightly moist potting soil. Place the tuber in the pot (eye facing up/neck up) and cover with 1–2 inches of soil.

 * The Golden Rule: Do not water the pot until you see green sprouts. Tubers have no roots yet, so wet soil will cause them to rot.

 * Light & Heat: Place pots in a warm spot (20°C is ideal). Once sprouts appear, move them under grow lights or to a very sunny south-facing window.

 * Hardening Off: Before planting out, move your pots outside for a few hours a day for a week to get them used to the wind and sun.

Option 2: Direct Planting (The Low Maintenance Route)
Best for: Gardeners who want a simpler process or don't have indoor space for pots. If you don't want the fuss of indoor pots, you can absolutely plant directly into the ground! Just know that your flowers will likely start blooming later in the season (late August/September).

 * Wait for Warmth: This is the most important step. Do not plant until all danger of frost has passed and the soil has warmed up (usually early to mid-June in our region). Cold, wet soil = rot.

 * Dig: Dig a hole about 4–6 inches deep.

 * Plant: Place the tuber horizontally with the "eye" facing up. Add a handful of bone meal or compost if you like.

 * Cover: Backfill with soil.

 * Watering: Unless your soil is bone dry, hold off on heavy watering until you see the green shoots poke through the ground.

Grower's Tip: Can't decide? Try a mix! Start your "must-have" or late-blooming varieties (like Dinnerplates) indoors to ensure they flower, and direct plant the rest to save space.
 
Steps for Success (Both Methods)
Whether you start indoors or plant directly, follow these steps once your plants are growing in the garden:

1. Stake Immediately
   Dahlias are heavy! Place your stake (tomato stake, rebar, or heavy bamboo) at the time of planting. If you drive a stake in later, you risk spearing the tuber underground
   
   
2. The "Pinch" (Don't Skip This!)
   It feels wrong to cut a healthy plant, but it is necessary for more blooms.
    * When: When your plant is about 12 inches tall.
    * How: Snip off the very top center stem, just above a set of leaves.
    * Why: This forces the plant to send up multiple stems from the base, giving you a bushier plant with 10x more flowers.
   
   
3. Summer Care
    * Watering: Dahlias are thirsty once they are big. Deep watering 2–3 times a week is better than a light sprinkle every day.
    * Cutting: The more you cut, the more they bloom! Don't be afraid to harvest flowers for bouquets. If you leave dead flowers on the plant ("deadheading"), the plant will stop producing new buds.
   
   
4. Winter Storage (Digging)
   In our climate, dahlias cannot survive winter in the ground. You must dig them up to save them for next year.
   
    * When to Dig: The goal is to ensure your tubers are fully mature. Dahlias generally need at least 120 days in the ground to produce viable tubers that store well.
   
      * Option A: Wait for a hard frost to turn the foliage black (the traditional method).
   
      * Option B: If frost hasn't hit yet but your plants have been growing for 120 days (usually by mid-October), you can cut them down yourself.
   
    * The "Curing" Period: Whether you wait for frost or cut them down green, cut the stalks to about 6 inches tall and leave them in the ground for another 4–5 days. This signals the tubers to "skin up" and helps the eyes set.
   
    * Dig: After that waiting period, gently lift the tuber clump with a pitchfork, being careful not to break the necks.
   
    * Dry & Store: Wash off the soil, let them dry for 24 hours (don't let them shrivel), and pack them in peat moss, vermiculite, or wood shavings. Store in a cool, frost-free spot (4–10°C).