Growing Concerns 537: Shade to sun garden, planting under eaves

Early Fall!

When trees are removed and sun streams in it's time to make changes in the shady beds below

 

Dear Janet,

We have to take down nine old ash trees!

It is so disheartening. We're bewildered. Should we just switch all our shady gardens to sunny gardens because of this problem?

P.A.,

Dear P.A.,

It is bewildering to make this kind of transition. However, I've seen it happen other times and know you will get through it. You may even be pleasantly surprised in some ways.

Don't change anything right away. Many plants we grow in the shade are only tolerating the low light and will actually grow better in sun. Others can perform well in sun if given extra water.

You'll be surprised at the watering. With trees gone that could each take up a hundred gallons of water per day or more, you may be able to turn what were relatively dry beds into moist gardens without any change in irrigation schedule.

Watch and see. Move plants that burn in the sun. Replace them with sun-loving species that are of similar shape, texture and bloom time so you can maintain your design. For instance, if astilbe begins to scorch without the trees' shade, look for a replacement that is mounded and fine in texture, as astilbe is. "Fine" means lacy of leaf as opposed to having large, bold leaves. You might settle on white and pink veronica (Veronica spicata'Icicle' and "Fox').

Should you give up a hosta, substitute something else low and mounded with coarse texture (large leaves) such as large-flowered comfrey (Symphytum grandiflorum) or sea kale (Crambe maritima).

For perennials or shrubs that don't come right out and burn but seem to be faltering, yet you really want to keep them: Promise them you're working on it, plant a new tree nearby and baby them for a few years until the tree begins to cast a bit of shade. Position the tree so it blocks the noon to 3 p.m. sun.

Don't plant big trees, trying to speed things up. Plant trees with trunks no bigger than one inch in diameter. The smaller trees, which lose less root in the move than larger trees, will take so rapidly that they will be larger, quicker, than anything you buy big.

Keep this in mind: At least you will know what's going on. When the opposite happens -- sunny areas turn into shade -- it's gradual and people don't recognize the change. Often, they think something else is wrong with their plants!

 

Dear Janet,

Any advice on planting for the perimeter of a house that is dry and shade? I have gotten four o'clocks to grow from seed but otherwise there is a line in the garden where the eaves end. 28 inch eaves!

T.P.,

Dear T.P.,

There are no magic spells for dry places under eaves. It is, by the way, the drought rather than the shade that makes it so hard to grow there.

I used to try to grow under eaves, too. Eventually I took a step back, found enlightenment and now I encourage others with this problem to do the same. That is, take an objective look at the site from its main viewing locations and ask yourself, "Why do I need to plant there?"

When seen from the road or the yard, the bare space between plants and wall isn't visible. Anything growing near the foundation, even though it stops two feet shy, appears to be snugged right up to the house. When it is viewed from a porch or someplace close by, that gap is not an eyesore but is recognizable as a humane working space for a window washer. Seen from inside -- well, usually, the two feet nearest the wall are invisible to anyone looking out a window.

If it's the straight edge where growth stops that bothers you, plant drought tolerant plants here and there just outside the eaves, things at least three feet in diameter at maturity. In shrubs that might be blue mist spirea (Caryopteris x clandonensis) for sun, and for shadier sites dwarf Oregon grapeholly (Mahonia aquifolium compactum) or dwarf deutzia (Deutzia 'Nikko'). In perennials, I'd rely on goatsbeard (Aruncus dioicus) in shade and false indigo (Baptisia australis) in sun. For groundcovers, you probably can't beat a colony of big root perennial geranium (Geranium macrorrhizum) or bishop's hat (Epimedium species).

Keep these plantings well watered as they establish just beyond the eaves. They will expand not only toward the open sky but backward into drier areas, using the water collected by roots outside the eaves to supply their drier sides. Their bulk will break up that annoying straight line.

 

Green thumbs up

to S.C.  who has a novel alternative to burlap for keeping winter sun off broadleaf evergreens. S.C.'s sinking metal pipes into the ground right now and will later slide the handles of golf- and beach umbrellas into those pipes to block the sun from the shrubs and color the winter landscape, too! 

 

Green thumbs down

to putting tender perennial roots into storage if they have any soft spots or wounds. Already rotting or ripe-for-rotting spots will only infect other stored items. Throw them out! The dahlia, canna, caladium or elephant ear you planted in spring has grown or multiplied ten fold so you can afford to let some go!

 

Originally published 10/11/03