Growing Dahlias in High Heat

You love dahlias but you live in the land of scorching sun! What to do? Well- here’s a blog full of tips for growing with more success in high heat.

I’ve written a lot on this topic with tips on different methods for success in high heat but I’ve never compiled it into one place. Some of this will be links to past blogs (no sense in re-writing it all here) and some will be newer methods we have learned over the years. So here goes:

1. Variety is important. Some varieties just don’t work super well. I wrote about how I choose varieties in part 4 of the Dahlia Game Plan series last winter. I also have a whole module about choosing varieties in my Dahlia Growing for Beginners Virtual Workshop.

2. Watering is crucial. Several years ago I started experimenting with pulse watering. It was a game changer for keeping dahlias hydrated in high heat! I wouldn’t go back to my old method now. Read more on that here

3. Shade- Shade cloth or location- either one works. So we grow 1000’s - it’s not practical for us to use shade cloth. Would it help - Sure! But our fields are multiple places and too big to do it cost effectively. This is why I’ve worked on other methods (as listed in this blog) to give us success growing in high heat. But for smaller growing situations, shade can be a powerful too.

4. Planting time- This is really important. You need to get plants established before your climate and soil get too warm. Tubers can cook if planted in soil that’s too hot. This timing will depend on your climate. For us, it means get them done by end of May. If you have to plant in warmer soil, try a rooted cutting that’s been potted up. Those roots will establish faster and you can water it which cools your soil.

5. Surround (Kaolin Clay) - We use this as a crop protectant— helps keep early season powdery mildew at bay, keeps mites and thrip pressure lower but also cools the plants several degrees. Longer form blog on it here.

6. Pruning- Dahlias respond very well to pruning. Cutting plant back by half is a great method to employ mid summer during the really hot part. This lowers the stress level on your plants. Usually early July is our timing if we choose to cut back. This method works well if you overwinter your dahlias and don’t have control over when they sprout. You’ll get blooms again 6-8 weeks after pruning.

7. Patience- growing a plant in an enviroment that is less than desirable for it is going to take time to learn. Dahlias can thrive in a lot of places but high heat is a bit of a learning curve. So expect that it will take several years to learn how to do it successfully.

However, I hope these tips will help! Do you have any great high heat growing tips? Send them my way!