Problems with new penstemon and balloon flower

Asked June 13, 2018, 8:50 PM EDT

I have some new plants from the Resource program that are struggling. Attached are photos of the leaves from the balloon flower, which are browning, and from the penstemon (I believe) with white spots. They are planted in good soil but may be getting too much sun (6 hrs, and of course it's been hot). I planted 2 weeks ago, and I've been giving some extra water (1 gallon every 4-7 days). Can you tell me what the browning and spots may be due to (e.g., too much sun, too little water, too much water)?

Boulder County Colorado

3 Responses

The pictures show multiple things going on with the bush. I would encourage you to bring in a sample to the extension office for us to see. You need to remove the diseased parts of the plants and make sure that you clean your cutters to not spread the disease. Do not compost the diseased limbs. When you water use a sprayer to wash off the aphids on the leaves. You can try to wash the leaves with a soap and water spray to see if that would help. For more information about powdery mildew go to the CSU web sight fact site 2.902 and 2.903 for more information.

Can you clarify? There are two plants -- is there one in particular you are referring to? You also refer to aphids and to powdery mildew, -- are you saying that you see signs of both? I have not seen any signs of aphids.


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It may be that the plants are just in a bit of shock and will settle in to their new home soon. I would be careful to not over or under water in the near term as leaves can brown from either. If you're still having problems in a few weeks, I would suggest that you bring some sample leaves to our office for further evaluation.