Prepping- Dahlia Style!

We’ve been in the middle of a heatwave like most of the Southeast and a large part of the country over the past week. Through the years I’ve learned a few tricks to combat the effects of heatwaves. Today I’m sharing what I did late last week to prepare for the heat wave.

The first thing to consider is what stage of growth your dahlias are currently. For example, I have a field of very small rooted cuttings that was planted out a week before this heat wave. Not great timing, I know. But it couldn’t be helped. We had reached the “now or never” point in the season and it all had to get planted. But I knew that left alone, those little cuttings would have died. So I remembered that I had a large piece of shade cloth ( this is a piece that fits a farmers friend hoop house). I have safety caps on top of my support posts so I knew we could just drape it over that field without ripping it. It took us about 20 minutes from start to finish. Easy peasy!
The other thing I did for this field was add mulch- we had a lot of rain early in the season and it washed off a lot of our mulch. I also made sure it got extra water for any day during this heat wave that we didn’t get rain. So far— they are looking pretty good!

Second major task we did was to use the “dahlia sunscreen”. This is the Surround spray - (kaolin clay). This spray will help with bug prevention but it also will lower the temperature around your plants. I can only use this for the first half of the season. After we pinch, I stop because I don’t want it on the stems/blooms I’m selling. It doesn’t wash fully off. Luckily we had just pinched the plants so I was safe for one more spray. A week later and I would have been out of my window. (the picture below was taken after 2 big storms had come through, so some has washed off)

Third thing I did was a little cutting back. I had 2 rows of 3rd year dahlias that needed to slow down a little bit. They were blooming too early and the petals were burning in the extreme heat. So I cut them back by around 60%. Now I’ll confess I did this the day before the heatwave started. I don’t recommend that— try to pay attention to the weather and do this several days before your heatwave. But they are okay. It was better that I did it, even though my timing wasn’t the best.

Lastly, another technique that I used partially. I used a sprinkler to overhead water everything on day 1 of the heatwave. I wanted to add extra water but I also wanted to bring up my humidity levels in the field. Raising those will help prevent powdery mildew. PM and spider mites love to reek havoc when it gets hot and dry. I would have continued the sprinkler at least every other day but we got rain (surprisingly) on days 3 and 4 of the heat wave.

Those are just a few of my tricks from many years going through heat waves. We always get a few but as long as your plants are well established and you keep them irrigated well- they usually make it through!