Insider’s Guide to Selecting Healthy Trees and Shrubs
Get to the root of the issues!
There are two main things to consider when choosing a plant to purchase. First, choosing the right plant for the right spot, and second selecting a quality plant to buy. As for choosing the right plant for the spot, there’s an app for that! Botany Buddy’s tree and shrub finder was designed specifically for this purpose. As for choosing a quality plant to purchase, this post for that.
Trees and shrubs come packaged for sale in three main forms: containerized, balled and burlapped and bare root. The best of these to buy will depend on what you are using them for. Containerized trees and shrubs are ideal for planting in prepared beds, individual holes in the ground, or in pots. Balled and burlapped plants are best when planting in beds, or individual holes in the grounds, but do not do as well in containers. Bare root plants do best in pots or directly in unprepared ground. Larger bare root plants (shrubs over 6″ tall or trees over 12″ tall) perform best if planted in pots in the spring and allowed to root out before planting into the ground later in the season.
There are several factors to look at when choosing a plant to purchase depending on the packaging.
1.) Bare root plants can never be allowed to have the roots dry out. Healthy bare root plants will have small white fibrous roots it they have been properly cared for. If they have dried out they may be brown but still be viable. This can be determined by scratching the root to see if it is green or white underneath. If it is, pruning them back by 20% and immediatelysoaking them in water and root stimulator (Vitamin B1) can cause the roots to sprout new growth. If the roots are dry and brittle or soft and smooshy don’t buy the plant. The roots are probablydead.
It is also important that bare root plants have an equal or greater amount of root growth than plant growth. Pruning back the top can solve this but it not done correctly may hurt the plant’s eventual shape and removes valuable nutrients stored in the bark that can be used for establishment.
2.) Container plants should never be allowed to dry out. Whenever purchasing a containerized plant, remove the pot and inspect the roots. The rules on healthy roots are the same as for bare roots. If the plants have small white fibrous roots they have been properly cared for. If they have dried out they may be brown but still be viable. Just scratch the root to see if it is green or white underneath. If it is, score the roots and rough up the ball when planting. With immediate watering they can be caused to resprout. However it typically takes an entire growing season for the roots to get back to a really healthy state. This can greatly affect survival and slow down growth. The energy stored in the branches of a plant can keep it look completely healthy for an entire season even if the root system is dead. This is why you should always inspect the roots.
There are also signs to look for that you should completely avoid. Some plants may have been left in a pot so long that the roots will have girdled themselves. They will have circled around the pot so many times that they are strangling themselves and will eventually cut off their own circulation. Another symptom of being in a pot too long is that the plant may have used all the soil in the the pot and be nothing but a mass of roots. They can still be kept alive in the pot with daily watering and regular fertilizing, but once planted it creates an air pocket that eventually causes the plant to dry and freeze out over winter. If the pot is big but fells surprisingly light, or blows over in the nursery with just the slightest breeze this is probably the case. This makes them easy to spot from a distance. These roots are a little tight, but healthy!
Finally, the plant needs to have enough root mass to support the plant. A plant should have ten inches diameter of pot for every 12” of height on top. On trees, they should have 20” diameter of root for the first caliper inch of truck, and 10” for every inch of trunk after. If an evergreen is grown in a pot, the width of the foliage and branches should not be more than 50% wider than the width of the pot. It is acceptable for a plant to have been pruned back to stay in a pot and can be benefitial to the long term habit of the plant, as long as the roots have not out grown the pot.
3.) Balling and burlapping plants is typically reserved for very large shrubs, over 24” in evergreens and 36” in deciduous plants, or for trees. Very rarely are plants bug by hand in the field due to labor costs. As mechanical digging has grown in popularity, so have the problems associated with it. As a result it is recommended that if all possible you hire the person selling the plant to install it with a warranty on both the plant and the labor. I would never buy balled and burlapped material from a mass retailer that doesn’t specialize in plants.
Healthy balled and burlapped plants will have been dug when the soil is moist but not soggy. They are typically grown in soil with a little clay to help hold the ball together, and will be wrapped in natural fiber and bound with biodegradable twine. Balled and Burlapped plants should always be shipped within 24 hours of being dug and immediately covered in mulch or gravel, and watered upon receiving. The roots or outer edge of soil should never be allowed to dry out. Once they have, it can take over a year for active root growth to resume. Any time roots can be seen emerging from the burlap into the surrounding mulch you can be assured the root system is healthy and has been well cared for.
These balls are actually a little small.
There are a few things to always look out for when selecting a balled and burlapped plant. Never buy a plant that has a mushy or crumbly ball. Most likely the roots have been broken apart. Balls that are dry and hard with no sign of new root growth emerging from the fabric are probably not viable no matter how good the top looks. When the ball is lifted from the ground, if the bottom falls out or the burlap sags like a wet diaper, the plant has been sitting in water for a prolonged period of time and the bottom has rotted out. At the top of the ball there should be a string encircling the trunk of the tree or base of the shrub. If this sting has cut into the bark, or the bark has grown around it, the plant has probably been girdled and will most likely suffer or die. Finally, many nurseries will rewrap the ball with fresh burlap if a plant has set on the lot too long. If the plant looks like it has been on the lot awhile, but the ball does not, don’t be afraid to look under the burlap to see what is underneath.
Sizing the root mass compared to the top.
There are a few standards that should be met regarding the size of the ball. The size of the ball needs to be proportionate to the top of the plant depending on what type of plant it is. Also when selecting a tree, it is best if the ball is large enough to support the top without need for staking. Some good standard ratios for ball size are detailed below. These numbers are based upon ANLA standards, and adjusted for the reality of current digging equipment and techniques. The are also chosen to make sure you get the best stock, not the minimum standard.
Coniferous and Evergreen Trees 18″ of ball for the 1st 3′ of height and 10” of ball for each additional 1′ of height.
Coniferous or Evergreen Shrubs 10” of ball for the 1st 1′ of width, and 6” of ball for each additional 1′ of width.
Deciduous Trees 18” of ball for the 1st caliper inch of trunk and 10” of ball for each additional caliper inch of trunk.
Deciduous Shrubs 12” of ball for the 1st 1′ of height and 12” of ball for each additional 1′ of height.
Broadleaf Evergreen Trees 18” of ball for the 1st caliper inch of trunk and 10” of ball for each additional caliper inch of trunk.
Broadleaf Evergreen Shrubs 12” of ball for the 1st caliper inch of trunk and 6″ of ball for each additional foot of height.
Balled and burlapped plants are always best handled by experienced gardeners or professionals.
There are many more things to take into consideration when selecting plants such as the branching structure, disease, the shape, and variety, but the most important thing to the health of the plant is the roots. We will bring you more on pruning and shape later, but when buying at tree or shrub they almost all have pruning issues. Mainly becasue the are being pruned to grow roots, fit in a retail space, and sell…not Grow! That topic needs its own post.
As for disease and insects, those are common as well in nurseries. However, on deciduous trees, as long as the damage is limited to leaves it won’t matter. They will fall off in the fall, and you really don’t want much growth in the first year. So if the plant has a nice shape and is green some spots on the leaves won’t hurt. As for evergreens, if it has an orangish or brown cast avoid it. There are probably mites in there! Evergreens with a determinate growth rate cannot grow from old wood if it the loose branches, so be sure the plant is healthy. However, if nurseries killed everything that got on their plants they would probably killing you too. So if you see a tree that doesn’t have scarred up bark, and broken branches everywhere, but has a few spots on the leaves, as long as it has the root system and has been handled as described above you should be successful.
The bottom line is if you want to be successful you have to dig a little deeper and get to the root of things. As long as you water a plant well and keep it wet until you get it in the ground you should be succesful if you start with a healthy plant. Have you ever wondered why retailers guarantee plants? It is because they know if you get it home, it has a better chance of surviving than if it stays with them.
Next Weeks Blogs…Planting and Watering: Learn how to keep things alive and make them thrive!
