Tracking Down An ID

I love unraveling puzzling plant identifications. It would be great if there was always a straightforward way to go about it, but there isn’t always. If I’m lucky, the plant is in one of the references that gives you a logical way to go about figuring out the puzzle. I like to use Newcomb’s Wildflower Guide, The Tree Identification Book and the Shrub Identification Book by George W.D.Symonds, and Key to Common Woody Landscape Plants in the Midwest by Benton M. Stidd and Robert D. Henry.

To use any of these, you need to have a lot of information about the plant. A stem with leaves really helps but sometimes, especially with wildflowers and perennials, you need flowers and/or fruit or information about where the plant is growing.

I used almost all of these to identify a small flowering shrub I saw in Brown County State Park in southern Indiana. The Symonds books are great because you can use the plant part you have and match it to the photos in the book. Then, you can check that the other plant parts match. So, I looked for leaves that matched – alternate, simple, entire – and then checked each to see if the flowers matched.

I kept coming up with blueberry, which quite surprised me. Blueberries need acid soil and I wasn’t sure the soil in Brown County was acidic. We are very fortunate that Soil Surveys are now on-line (see http://websoilsurvey.nrcs.usda.gov/app/WebSoilSurvey.aspx). I was able to determine the exact soil type in which the plant was growing. Unfortunately, pH of the soil wasn’t listed, but I have a list of all soil types in Indiana that told me that the soil in that area of Brown County was indeed acidic.


But which blueberry was it? Symonds book suggested it was Vaccinium stamineum or deerberry. The flowers are flared open unlike other blueberries and there are small leaves close to the flowers. I was fortunate to find this plant on the Missouri Plants webpage (an excellent resource) and confirmed it with a colleague at Purdue.

So, using a good reference which gave details of both leaves and flowers, double-checking site conditions, and verifying with experts led me to the ID. Believe it or not, this is an example of a do-able ID. When the plant is not in any of your references or when you have to resort to looking through photos to see if you can find a match, then you’re in trouble!

Plants Change Color

It’s not unusual for fresh new growth to be a different color than older leaves. You can easily see the contrast on yew, whose new leaves are light green compared to darker mature leaves. The new leaves of honey locust will often start out yellow-green then mature to a darker green.

These color changes are normal. There are some other color changes, however, to which you should pay attention. If your plant is a variety with colored foliage – yellow, purple, black, variegated – instead of plain green, check it periodically for reversions. These types of plants will sometimes produce a stem that has plain green leaves. That stem has “reverted” or changed back to the normal color for the plant. These stems will often be more robust than those with colored leaves and may overgrow the rest of the plant. After a year or two your once highly colored and attractive plant is just plain green.

If you find a stem that has reverted, the cure is simple - just cut it out. There is no way to prevent reversions from happening. Some plants with colored foliage never produce a reverted stem. In some species and varieties, it happens frequently. If you do find a reversion, make a note to inspect the plant a couple of times a year. You need to remove stems that have reverted as soon as possible. The photo is Physocarpus Diabolo®, a black-leaved cultivar with a branch that has reverted to all-green leaves.

Back from Arizona!

IndyGardening Blog is back with my return from a long vacation in Arizona. What a difference from last May! I didn’t expect to see tulips, redbuds and dogwoods in full bloom in early May. What a cool spring it’s been!

There are lots of things blooming this time of year, so identifying plants can be a challenge. Here’s one I was asked to ID recently. No photos, just a word description. Do you know what it is?

- Three leaves something like a rose leaf with very fine serrations)
- Trunk is 2-3 inches in diameter and 6-8 feet tall.
- Growing along but not in a waterway with some direct sunlight but woods on the back side.
- Flowers are white and remain bell shaped, do not open up as many flowers do.
- Seed pods from last year are three sided. The shape is something like a filbert nut.

The real key here is the leaf with three leaflets. There aren’t that many plants with this type of leaf (called trifoliate). A quick look through George W.D. Symonds Tree and Shrub Identification books gave a couple of options and the “flowers that don’t open” and 3-sided fruit nailed it down.

This is a fairly good description of American bladdernut, Staphylea trifolia. It is native to much of the eastern US, growing as a tall suckering
shrub rather than a tree. The leaves are opposite with three finely-toothed leaflets. The flowers are small white bells that appear in clusters from April into May. By September you’ll find a papery, inflated, balloon-like, three-sided fruit.

You can grow this native in moist, well-drained soils in sun but also in fairly deep shade. It won’t knock your socks off but can be a nice effect in a naturalized area.
You can find it at both the IMA and the Indianapolis Zoo.

Spring is here!

Spring must be here. I’ve seen the first daffodils and there are even a few squill. Gardeners all over Indianapolis are planting pansies to brighten up still-dreary landscapes. One innovative gardener even mixed lettuce in with the pansies for added interest.

It’s time to start thinking about fertilizing your bulbs. The roots of bulbs absorb the most nutrients as the leaves emerge from the soil, so now is the time to fertilize. Apply 1-2 pounds of 10-10-10 or equivalent for every 100 square feet. To estimate the volume of 1 pound of fertilizer, assume one liquid ounce is equivalent to one dry ounce, so 1 pounds of fertilizer is 16 dry ounces, equivalent to 16 liquid ounces or two cups. A little math will then tell you that 1 pound fertilizer for 100 square feet is about the same as 1 teaspoon for 1 square foot.

Unfortunately, I’m going to miss this year’s bulb show. I’ll be out of town.

Fortunately, I’m going to be in Arizona. I’ll do my best to give you a view of gardening in Arizona, so check this blog frequently.

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One of my favorite daffodils is a variety called Tete-a-Tete. It's only about 6 inches and is one of the earliest daffodils to bloom. It's unusual because there are often two flowers on a single flower stem.

Time to start the lawnmowers?

Our wet, cold March is slowly creeping by. Already the cool season lawn grasses common in Indiana – Kentucky bluegrass and tall fescue – have begun to grow. Though mowing now is likely to leave ruts in the wet soil, it’s time to think about that first time around the yard.

I recently attended a seminar by one of Purdue’s turf experts, Dr. Zac Reicher. He made some interesting points:
- In spring, grass grows quickly and should be mown often. The first mowing can make the grass shorter than 3 inches, but for all future mowings, set the lawnmower height at 3-4”.
- Wet grass may tempt you to wait a few days to mow. Don’t! If you have to choose between two evils – mowing wet grass and letting the grass get really tall before you mow – choose to mow wet grass.
- If you’ve already applied a crabgrass prevention product, great! It will stay active for the next couple of months and keep crabgrass from germinating in your yard. If you haven’t, make sure to get the product on your lawn by the middle of April. Look closely at the product label and choose the brand with the least amount of nitrogen fertilizer. If it has no fertilizer in it at all, that’s even better. April is not the time to apply lawn fertilizer. It will only make your grass grow and increase your mowing. For information on how to calculate the amount of nitrogen, see http://www.agry.purdue.edu/turf/tips/2008/3_17preemergence.html.- The best time to treat broadleaf weeds in your lawn is autumn. If you still have a few dandelions popping up, wait until they are blooming, then spot treat just the dandelions. They will be more susceptible to the herbicide at that time.

Time to Prune?

Many people know that late winter/early spring is a great time to prune many trees and shrubs. So, grab your pruners and rush right out – NO, wait!

It’s important to remember that not all plants need to be pruned in spring. Some plants, many viburnums for example, don’t need annual pruning. Always remember why you are pruning. There are several good reasons to prune in early spring:
- To remove broken or dead branches. These will be easy to see early in the season but can also be pruned out any time you notice them.
- To remove branches that cross (see photo to right) or branches that are growing inward or straight up. Such branches will crowd the major scaffolding branches of the plant, reducing light penetration. The plant will not grow as well as be as healthy unless some of the excess is removed.
- To improve plant structure. Especially on a young tree, you may find you need to remove a double leader (see photo to left) or cut off branches growing from a narrow crotch angle or that are crowded on one side of the trunk.

It’s also important to remember that not all trees and shrubs should be pruned in late winter/early spring. If the plant is grown mainly for summer foliage, now is the time to prune. However, if the plant is grown for spring flowers – forsythia, lilac, spirea, crabapples, hawthorns, and dogwoods, to name a few – don’t prune now. These shrubs and trees should be pruned after flowering.

Itching to Garden?

It continues to be cold and snowy in Indianapolis. Mother Nature is taking her time this year. The past three winters gave us winter aconite and other early spring flowers by mid-February. Not this year!

If you want to get out into the garden, maybe it’s time to think about your tall German iris (also called bearded iris). If you haven’t yet, cut back and remove last year’s leaves and any surrounding plant debris. This will help you control two different iris pests.

Iris borers are the larval, or caterpillar, stage of a moth. The adult lays eggs in the iris leaves and debris in late summer. In spring, the eggs hatch. The caterpillar climbs onto new iris leaves, burrows into them, and moves down into the iris rhizome, where it feeds. Eliminating the eggs by gathering and discarding all the old plant debris will go a long way toward controlling this pest. For more information on iris borers see http://www.extension.umn.edu/yardandgarden/ygbriefs/e122irisborer.html.

Another pest that attacks iris is iris leaf spot. This is a fungal disease that infects new leaves and causes spots on the leaves and lack of vigor. Again, you can avoid chemicals by simply cleaning up and discarding the old iris leaves. For more information on iris leaf spot see http://www.ext.vt.edu/pubs/plantdiseasefs/450-600/450-600.html.

Of course, you can always change the plant. Siberian iris are resistant to both of these pests.