VinceR
Newly Registered
Posts: 4
Joined: Sat Apr 12, 2008 10:22 am
Location: Oakhurst, NJ

Too much sun for columbine, hosta and azaleas?

Should columbine, hosta and azaleas be shielded from too much sun?

I have azaleas alogside the house foundation on the west side. By the time they get sun, it is afternoon. In the summer, it just seems like the azaleas are baking. Should they be moved to an area of dappled shade?

Similar questions for columbine and hosta.

Thanks,
VinceR
VinceR
Oakhurst, NJ

MaineDesigner
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Posts: 439
Joined: Thu Nov 09, 2006 11:17 am
Location: Midcoast Maine, Zone 5b

You are a little out of my region so don't take this to the bank but in Northern New England or the Upper Midwest (Minnesota & Wisconsin) the deciduous azaleas do fine in full sun and I wouldn't recommend less than four to six hours of sun. Most evergreen azaleas aren't fully hardy here so I can't help you with those. For hostas it depends on the cultivar, 'Royal Standard' for example is fine with six hours of full sun here but most cultivars do better with AM light or dappled shade. I have had no problems with columbines in full sun - if the drainage is adequate their biggest issues tend to be leaf miners or sawflies.

NewjerseyTea
Senior Member
Posts: 143
Joined: Sat Feb 23, 2008 10:14 am
Location: Piedmont Area, Northern NJ

Hi VinceR,
Do you have an evergreen PJM azalea that is used frequently in older foundation plantings in NJ? You can usually tell if it blooms intense fuschia or purple and the leaves are evergreen . If so they generally can take quite a bit of sun. I had one in a grassy side strip about 8ft. from the foundation in southwest summer sun for years. They lose their flowers quickly in that spot if the weather gets hot early.
What is the problem you are noticing with your azaleas?

As far as the hostas go most seem to prefer morning light and dappled shade as Maine Designer suggested. I do see some in neighboring gardens in full sun and most end up with scorched looking leaves.
I do grow the native red wild columbine (Aquilegia canadensis) among grasses in a sunny prairie garden but also grow alot (purple blooming none native) in a slightly shadier woodland garden. They do need some sun to bloom well but the leaves stay green longer in the shadier area. If you cut the leaves back hard after they start to look ratty (mine are usually attacked heavily by leaf miners) you'll get a new flush of green growth. Just make sure you let the flowers go to seed as they can be a short lived perennial. I think the columbine is one of my favorite flowers. I wish the red natives were as prolific for me as the others.

VinceR
Newly Registered
Posts: 4
Joined: Sat Apr 12, 2008 10:22 am
Location: Oakhurst, NJ

Too much sun?

Thanks for the replies.

The azaleas are evergreen, crimson-flowered. Leaves become dappled with yellow-brown spots, reminding me of spider mite infestation, but I do not get any mites to drop onto a white paper if I tap the twig, nor I do not get red splotches if I "squish" a few leaves. I also have been spraying with insecticides. The plants just seem to slowly be dying. I fertiilize with 5-10-5.

As to the hosta: they do get to look scorched by the end of the summer, so I guess too much sun is the problem.
VinceR
Oakhurst, NJ

MaineDesigner
Green Thumb
Posts: 439
Joined: Thu Nov 09, 2006 11:17 am
Location: Midcoast Maine, Zone 5b

There might be another consideration here. Check your soil moisture. With more light and more heat the metabolism of the plant increases (up to a point but for the sake of simplicity let 's leave it at that) which means (among other things) that the plant is using more moisture. Both azaleas and hostas prefer soils slightly on the damp side. The caveat is that heavy, wet soils will promote phytophthora problems with the azalea so make sure you have good drainage. Are you sure your soil is acidic? Sometimes concrete foundations can raise the pH of the soil nearby. Is there lots of organic material in the soil? Have you mulched the plants?
It is hard to tell from your description but you could have a fungal problem or it could just be sunburn.
Nothing you have mentioned suggests an insect problem to me so knock off the insecticides. Indiscriminately spraying insecticides with no specific identified target is never a good idea. Insecticides are ineffective against mites (they aren't insects).



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