And what’s not to love about dahlias?  They come in so many gorgeous colors and shapes.  They’re prolific and require little maintenance once you’ve got them situated for the summer.  You can dig them in the fall and save them for the next year and they even like to be divided so that you can easily multiply your stash.

We’re a little obsessed with them ourselves, and we’ve probably spent way to much on dahlias already.  We’ve been growing them for several years now and would like to think we’ve learned a thing or two about growing them in our climate.  We’re no experts, by any stretch of the imagination, but here are a few tips we’ve learned so far.

9 Tips for How to Grow Dahlias

1. Give dahlias a spot in the sun.

Plant your dahlias in full sun.  We’ve tried planting them in partial sun, but they didn’t thrive.  The more sun they get, the more flowers they seem to produce.  According to what I could dig up online, dahlias are native to Mexico so they can definitely take the heat.

2.Plant them after your garden soil has warmed.

Wait to plant them until the ground temperature is at least sixty degrees Fahrenheit and all danger of frost is past.  Cool, soggy dahlia tubers are not happy tubers and are prone to rot.  We often have cool, wet weather in May when we need to plant our tubers.  To minimize the chance for rot and to get a jump start on dahlia season, we’ve taken to potting up our tubers in April so that when we go to plant them in May, they’ll have leaves and stems and a lot less chance of rotting before they can start growing.  That means lugging alllll those pots inside when there’s threat of frost, but still, it’s worth it to have earlier blooms.

3. Plant them in loose, well-drained soil about 4″-6″ deep

Plant them in well-drained soil.  I’m repeating myself here, but if dahlias are planted in ground that doesn’t freely drain, they may rot before they have a chance to sprout leaves.  Dig a hole 4″-6″ deep and position your tuber so that the eyes or sprouts are facing up.  After their leaves make an appearance, they do benefit from consistent watering.  We used drip irrigation on them last year for the first time and it was revolutionary.  No more dragging heavy hoses all around the garden for hours.  We used a system from a company called DripWorks.  Dahlias can struggle with mildew later in the year.  Using drip irrigation can minimize the chance for that since the water is distributed at the roots and not onto the foliage.

4. Feed them occasionally

Dahlias can benefit from a bit of feeding.  We usually mix a granular fertilizer into the hole when we plant them, and then top dress with compost.  Unless you have poor soil, that may be enough to feed them throughout the summer.  We also apply some fertilizer throughout the growing season, being sure not to go to heavy on the nitrogen or they’ll be all bush and no bloom.

5. Give them room to grow

We like to space ours 18″-24″ apart.  This gives them room to sprawl (and they will!) plus good air circulation can ward off the threat of mildew.  If you’ve got plenty of room and are growing any dinnerplate varieties like Cafe au Lait or Fleurel, increase the space between plants.

6. Protect them

Slugs, snails, and earwigs are by far the worst threat to our dahlias.  They can mow through those beautiful blooms in a heartbreaking way.  We use an organic product called ‘Sluggo Plus’ to help with this problem.  Apply it when you plant your dahlias, and keep reapplying as needed.

7. Prune out the center stem

If you want a bushier plant, pinch or cut the main stem in the center of your dahlias when they’re about a foot high.  This will encourage it to branch and will result in more flowers.  It can feel counterintuitive to do this, especially if you’re feeling impatient for blooms.

8. Stake your dahlias

Dahlias really do need to be staked.  They can get top heavy, especially when they’re in full bloom, and especially when a summer thunderstorm comes whipping through.  Save yourself some heartache down the road and stake them soon after you plant them.  We were lazy with stakiing one year and didn’t get all of them staked well before a summer storm took out several of our three foot high dahlias just as they were beginning to bloom.  We use a combination of T stakes, wooden crosspieces, and horizontal netting that works pretty well if you’re growing lots of dahlias.  If you’re only growing a few, stake them individually, much as you would a tomato.

9. Keep them cut

Keep those blooms cut.  If you want them to bloom abundantly until frost, keep cutting them.  The best time to harvest them for bouquets is early morning when they’re well-hydrated.  Harvest them when they’re fully open since they don’t open much after they’re cut.  If you pick them in bud stage, you’ll be left with buds.  If you’re growing them to sell, cut them deeply to encourage longer stems and branching.  Otherwise, just remove the spent flowers.

That’s a lot of info to remember.  If you’d like to download a copy of our tips on how to grow dahlias, click on the photo below.

If you’re still looking to get your hands on a few tubers this year, Swan Island Dahlias is about to run an end of season sale.

So, has the dahlia bug bitten you?  Do you plan to grow any this year?  Or maybe you’ve been growing them for years and have a few tricks up your sleeve that you’d love to share.  I’d love to hear from you in the comments!

Rosita