Colorado_medium Colorado Extension

Questions received for Colorado through Ask an Expert.

(This group currently has 3 experts available to answer questions)

Questions asked to this group

Blight of aspen tree clumps

Two aspen clumps are slow to leaf out. The leaves are very sparse and the leaves that come are crinkled and have brown spots and appear wilted or blighted. Please see attached pictures.

Larimer County Colorado Posted 16 minutes ago

Lilac issues

I have attached three pictures. I hope they're clear. My Lilac bushes have some problems. Three appear to have only sprouted the very tips of the leaves? The others have curled leaves. I've been spraying with a natural mold, fungus spray but it doesn't appear to help... Please help me. Thank you!

Larimer County Colorado Posted about 3 hours ago

Fly Identification

I've had problems with bot flies in past summers. I've never seen the adults, but the warbles have had a devastating impact on my rabbits. While out feeding and watering today I came across an unusual fly. Is it a bot or another kind of fly? If you can zoom in on the picture, you'll see it's body has stripes almost like a bee.

El Paso County Colorado Posted about 5 hours ago

Treated ash not producing foliage

I am seeing several ash that are treated with ememectrin benzoate with little to no new foliage this year. Some are located right next to other like species which have fully come out. Any insight?

Adams County Colorado Posted about 7 hours ago

what is this caterpillar

Hi! We saw these on a white flower we'd gotten from home depot (Alyssum) and they are eating the flower petals, and they are hungry! I'm glad I saw them - they would have decimated the plant.

They are slightly hairy, light green cat's with black dots, and the white "stripes" are actually comprised of yellow and white dots.

What are they, and what will they turn into?

Thanks much!

Monika and Dean

Denver County Colorado Posted about 8 hours ago

restore ivy growth

My wall of English ivy was turned into a partial area of skeletonized vines by the drastic weather fluctuations over the past couple years. What can I do to restore growth to those severely stunted areas where only gray vines stretch up the wall?

Arapahoe County Colorado Posted about 8 hours ago

Fine Line Buckthorn

I planted these Fine Line Buckthorns last year but they don’t seem to be doing well. Is there anything I can do to help them?

Arapahoe County Colorado Posted about 9 hours ago

Can Aspen grow on a slope?

Hi there, I have a new aspen tree (11’ tall). I dug a large hole (almost double the root bundle size) that slopes upward (in an easterly direction). Now, I’ve hit a wall of rock about 1.5 hours into digging (so many little rocks). I’m about 2 inches shy of my goal hole depth/diameter. The hole I dug is about 2.5 feet wide and 1 foot deep. The attached photo shows the section (but I re-filled the area with dirt in frustration). Could I plant in this sloped hole? Will the new aspen likely survive if planted there? There’s plenty of room for the roots to grow out laterally or sideways. My neighbors have plenty of aspen growing out of the rocky slopes of their properties. I’m just trying to figure out what to do. We are at 7,950 feet elevation.

Jefferson County Colorado Posted about 11 hours ago

Extra pics for stunted growth

I wanted to provide some pics that showed more leaves And also the oak tree to go along with my question submitted a few minutes ago. I do have close up shots of leaves but I can only submit 3 photos. Thanks! Sue

Boulder County Colorado Posted about 13 hours ago

Stunted growth on trees and shrubs

I am searching for an answer and/or recommendations for this problem. I have 7 shrubs and an oak tree suffering from stunted growth this spring. The oak is multi-trucked and only occurring on the central trunk. This was professionally planted 5 years ago. I am afraid I will lose some of these this year because the leaves can not support the plants. It has been recommended by the Boulder County Extension Office that I examine the soil, fertilize and wait. This problem does not appear to be affecting my neighbors and I have compared sun exposure, exposure to the elements and general plant care over the winter with them. There does not appear to be a pest problem in the soil or on the plants. Much of the garden area is rocked with small mulch area around plants. I know that is not ideal but it has always been this way and a lot of these shrubs have been in place for years. Could this be a virus? Should I cut back these shrubs to protect the roots and hope to have growth next year? I can only upload 3 photos. The affected shrubs include sand cherry, Forsythia, dogwood, and a shrub that produces small red berries.

Boulder County Colorado Posted about 14 hours ago