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Understanding A vs B Grades

What it means and how it matters

Woody Warehouse Nursery grows over a quarter of a million trees and shrubs annually. Constant improvement and product excellence is at the core of what we do. But not every plant looks like it belongs on a magazine cover! To those plants that have minor cosmetic issues, we assign a B grade category. But what are the differences between an A and B grade? Is a B grade a truly inferior product that will fail?

Comparative photograph of A vs B Grade eastern redbud (Cercis canadensis). The slightly crooked trunk at the base of the plant (right) determines B grade disignation.


You Purchased B Grade, What Now?

Turn the B into an A!

Comparative photograph of A and B grade blackhaw viburnum (Viburnum prunifolium). The A grade speciman (left) is multistem with 3-5 stems per container and is full throughout the container. The B grade (right) is single-stem and not full throughtout the container.

It is a common misconception to view a B grade tree or shrub as inferior! Afterall, it’s not A grade so why do you want to buy that? As the chart to the left highlights, the differences are mostly cosmetic at a young developmental stage. These plants will grow out of it. What is paramount to the success or failure is the overall health and root structure. WWN strives to ensure all plants fit this. Because the criterion for separating is loosely based on cosmetics, with time and effort, you will not know the difference between the two types.

Now that you understand how we grade these two types, let’s discuss what to do with a B grade! Because these trees are young and actively growing you can easily correct this. Use bamboo, fiberglass, or any other type of stake available. Place the stake close to the trunk and drive into the substrate. Avoid damaging the main roots! If there is resistance, slightly change the path until in glides in easily. The stake should not be far away from the trunk. Using masking tape or any other semi-permeable material, pull the crooked section towards the stake. You will not be able to fully straighten it and don’t force it as compression injury can occur. Band the trunk every six inches. The finished product should look straight with a slight bow. Remove the stake within one growing year or less. Overtime, the trunk will straighten, and the B grade tree becomes A grade!

Converting a B grade shrub into an A grade is far simpler. Most shrubs will naturally fill out and over time, no other action may be necessary. For slower growing shrubs, consider a hard prune back 6” to 12” from ground. This will stimulate lateral branching that will help promote a rounded, full form. Hopefully this article has helped remove confusion on A vs B grade stock from WWN. Whatever grade you choose, you will be getting great native plants with superior fibrous roots. Enjoying planting!

Pro Tip #1 Correcting a Crooked Trunk

Use a bamboo or fiberglass stake. Place the stake close to the trunk of the tree opposite the crooked trunk. Use banding or masking tap, attach the stake to trunk every six inches. Remove after one year (or sooner).

Pro Tip # 2 Fix the Terminal Leader

Prune out damaged or stunted co-dominant leader. Using a stake or existing trunk, gently pull up the selected new leader and fix position with banding or masking tape. While unsightly initially, in a short time, a dominate terminal leader will be evident!

Pro Tip #3 Fill in the Thin Shrub

Most shrubs will naturally self-sucker over time. To even out the look, prune back the single stem to 6-12” which will allow the new branches to “catch-up”. Even if the shrub doesn’t sucker significantly, a hard prune back will encourage a full bushy appearance.