Wilty Dahlias

Are your dahlias sad? Do they droop and sag? You’re not alone! Unfortunately dahlias don’t always look happy and healthy- especially when growing in a hot climate.

So let’s talk about some of the possible causes:

We’ll start off with the obvious: Water— either too much or lack thereof
1. So if a dahlia wilts, the most likely thought is- It needs water right? Well that’s the first thing I check. Stick your finger down 1.5 inches into the soil and test the moisture level. If it’s dry, then it’s a good chance it does need water. But it’s also worth checking a few other things!
2. I always try to feel down to the tuber- you want to make sure it’s not rotting. If it’s rotting, then this is more likely the cause of the wilting. There’s not a ton you can do if it’s rotting. If it’s early enough in the season, I try to grab a cutting off of it. Or sometimes I will cut the plant back a little bit so that the tuber isn’t supporting so much green growth. But in reality these are last ditch efforts- you are probably going to lose it.
3. Now if the tuber is firm and the soil is moist - well that leads us to the next possible cause:

Verticillium Wilt- This is a soil borne fungal disease. It prevents water from moving through the vascular system - therefore showing up as wilting, yellowing foliage and dieback. There’s not a lot you can do unless you catch it really early. Sometimes you can chop the plant back hard and it will recover but you have to catch at the first sign of wilt. The problem is that it usually affects the plant in the lower portion of the stem and blocks water flow to the upper parts- which is why it’s so hard to deal with. Don’t compost any plant parts that you remove.
Prevention can help but it’s not a sure way to keep it away. Using a fungicide spray regimen before you see any signs can help prevent it or slow the onset. Soil solarization where you find it can be helpful too. But unfortunately, it’s usually a death sentence if you catch it too late.

Browning Leaves and Black Tips on new growth are also commonly seen in wilty dahlias. The browning - if it’s seen higher up on the plant is usually a sign of sun scorch. Lower brown leaves- like around the base of the plant may be signs of fungal issues. Black tips on new growth near the top of the plant are signs of a boron deficiency (Cafes love to get this!).

Next time you see a wilty dahlia, you know where to start to diagnose the problem! Want to be the first to know when we release a new blog post—
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