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How To Choose and Grow
Beautiful Evergreens in Iowa

Abies lasiocarpaIn a state with such long dreary winters, evergreens are a lovely way to add interest and life to our landscapes.

• Choose in winter.
The best time to decide what evergreens you want is in the winter. Of course you can decide any time of year, but when the landscape is barren is a great time to look at your landscape and really see what parts of it need some winter color and greenery (or, for that matter, need some screening of less-than-lovely views, like your neighbor's peeling garage).
• Choose very, very carefully.
There are so many evergreens that do wonderfully in Iowa. Don't end up with one that doesn’t. 

Many evergreens are not reliably hardy to Iowa
(Zone 4 for northern Iowa, Zones 5 for southern). Yet a disappointingly high number of Iowa garden centers carry evergreens not hardy to the area, and sometimes without even good labels that cite their hardiness zone. Many clerks will tell you a marginally hardy plant will be fine "in a protected spot" but that translates into "This plant is a gamble."

• Avoid winter die-back.
Even if an evergreen is hardy, it might be susceptible to what is called winter die-back,

Evergreens very
susceptible to die back:
Evergreens less-
susceptible to die back:
Arborvitae Juniper
Boxwood Pines
Fir Spruce

* Often have dieback just on the tips, which is usually easy to trim off.

• Cut back on die-back.
When you detect die-back in spring, just leave it. By June or early July, the damaged needles will fall off, helping you decide the true extent of the damage.

Except for boxwood and holly, most evergreens can't take a hard cutting back. They won't regenerate from that interior wood, which has few if any needles growing on it. They'll just be misshapen from a hard pruning.

If a plant is very damaged from winter die-back and it's not a boxwood or a holly, sorry, no doing a major pruning job. It's best to dig it up and pitch it. It has achieved what a good-humored horticulturalist I know terms "negative ornamental value." And that, my friends, translates into "ugly." Permanently.

• Keep pruning to a minimum.
Except for the dealing with any dead stuff, most evergreens do best with little or no pruning. When choosing evergreens, don't choose those that will get too big for the spot. Poor pruning of evergreens can permanently deform or even kill them.

Click here for more pruning information for evergreens in Iowa.

• Plant at the right time.
Spring is the best time, though early summer or September also will work. Avoid hot dry spells in summer or after September because it won't have a chance to get established. Work a few spadesful of compost into the planting hole and keep well watered for the next 2 to 3 weeks.

• Water when dry.
Once established, most evergreens do fine with Iowa's ample rainfalls. However, if fall is a little dry, give it an occasional deep soak or two. If the evergreen goes into winter well hydrated, its needles are less likely to get dried out and killed from winter dieback.

• Skip the fertilizer.
Most evergreens don't need fertilizing. However, the few evergreens that like acidic soil (azaleas, hollies, and rhododendrons),  do indeed benefit from a fertilizer that also acidifies the soil, available at most garden centers.

• Mulch well.
Mulch evergreens with 1-3 inches of mulch. This not only helps suppress weeds, it also keeps the soil moister and prevents thawing and heaving around the plant during the winter. Keep it about 1 inch away from the base of the plant, however, to prevent moisture problems.

• Wrap to prevent die-back.
A great way to prevent winter die-back is to wrap your evergreens with burlap in fall. This is especially important during the first 1-2 winters.

However, since many of us plant our evergreens precisely because we want to enjoy looking at them in the winter, after that first winter or two, you don't have to wrap them. However, if you have some really choice evergreens or you don't mind wrapping, it's an excellant way to assure protection.

Note: Thank you to Pam Maurer of Evergreen Gardens in Ames for reviewing this article.

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