Plant dahlias after the last frost when the soil reaches at least 60°F, usually between mid-April and early June, depending on your climate. That narrows it down, right? Don't worry. We have more.

First, find out your plant hardiness zone by using this link and entering your zip code in the top. After this, look up what the average last frost date is in your state for this zone.

The important thing is this is an ESTIMATE. You will still need to watch the local temperatures to verify when the last date will be below freezing at night.

Once you have determined last frost date, then you need to make sure the soil is warm enough. Some use a soil thermometer to test and this is what I would recommend for best accuracy. I, on the other hand, usually guess and sometimes guess wrong.

Sun

• Dahlias love sun and need at least 6-8 hours of sun.

Well draining soil

• If there is one thing you will hear over and over again, they don't like it too wet.
• If you have an area that runs a little wetter, start your tuber indoors and then wait until June when things dry out a little more to transplant outdoors.

Think of your plant like that one friend who never goes outside—then suddenly spends a full day in the sun and ends up burnt, miserable, and begging for aloe.

Don't do that to your plant! It needs to "harden off," which means gradually getting it used to the outdoors.

Here’s how:

• Start on a mild day – Warm, still, partly cloudy; water first.
• Gradually increase exposure – Start with an hour in shade, add time and sunlight daily.
• Adjust watering – Reduce gradually, but don’t let it wilt.
• Leave out overnight – If no frost risk; cover in cold regions.

1. Dig a hole that's 4–6 inches deep — just like a pup burying a favorite bone.
2. Place the tuber on its side in the hole
3. Cover the tuber with the soil.

American Dahlia Society recommends:

• 18" - 24" apart in one row
• keep rows 2-3' apart

Admittedly, I have planted a little closer but you want good air flow.

Also you will need to be diligent with watching for viruses and insect damage if you plant close together.

If you transplanted a dahlia from indoors to outdoors, you can do a light watering.

If you planted a tuber with no sprouts or growth, do not water the tuber unless the soil is extremely dry.

Once your dahlia has sprouted its first set of true leaves, you can begin watering.