Ailing Japanese lilac

Asked July 2, 2019, 11:59 AM EDT

Hello! Friends of Trees planted a Japanese Lilac for me last summer, and this year it's not doing great. FoT said they have another similar complaint from a different customer. Portland Nursery and FoT have both suggested sun scorch without any confidence, and recommended I turn to you. I didn't see any blooms on the tree, and the leaves have been turning brown all over. It does seem like new growth is still happening - tiny buds at where branches...branch. I've included a few photos. Would love to hear your take! I've never sprayed the leaves with anything, and since the weather has turned warmer I aim for the 10-15 gallons of water/week that's recommended. I didn't start that until the last 6 weeks or so, I'd guess, because we've had quite a bit of rain this spring. Thank you! Kalah

Multnomah County Oregon

3 Responses

It looks a lot like sun scorch to me. Are there any windows or cars parked where sunlight can be reflected? I have a garden window on the side of my house and I reliably get scorched leaves on a grape and quince that are directly inline. I couldn't find any fungal pests that would produce what you have pictured.

You could try putting lightweight spun polyester covering (one commercial name is Remay) which can reduce the intensity of light and may reduce further scorching.

I would continue your watering (you may only need ~ five gallons/week.)

It's not unusual for the plant to take 2-3 years to produce blooms. I would minimally prune for shape because lilacs set blooms now for next year.

Thank you so much Sara! I'll share this with Friends of Trees so they have more info about the trees they offer :) They reached back out to suggest it might be bacterial blight...any concern on your end of that possibility? If not, I think I'll wait things out a bit and hopefully regular water will get it back in tip top shape.

Cheers,
Kalah