Fielding Questions: Will this tree recover, best potentilla type, and the importance of seed-starting mix
This week, gardening columnist Don Kinzler gives the odds for survival of a flowering crabapple damaged by rabbits, recommends a potentilla type, and discusses the importance of seed-starting mix for new seedlings.
Q: What can I do to keep the tree in the photo healthy after a rabbit decided to have the bark for lunch. The red-flowering crabapple is two years old, and I really hate to replant and start all over. – Mike B.
A: I always optimistically believe in giving plants every chance possible, when there’s a route to recovery. But I also recognize when it’s time to let go.
Unfortunately, I see little hope for recovery when a tree such as yours is completely “girdled” by rabbit damage. When the bark is gnawed away into the white wood below, completely circling the trunk, the tree’s life-supporting system of water and food conduction is destroyed.
There are no pruning paints, sealers, or other products that can be applied to replace the life-giving tissue that rabbits have eaten away. Such trees sometimes contain enough internal sap in upper branches to begin leafing out in spring, but quickly expire when water and nutrients are no longer conducted upward for nourishment.
Because your tree guard preserved the lower trunk portion from damage, you could cut the tree down to an undamaged side twig, and train a sprout to become a new trunk, but that would take years to rebound back to your present tree size. If this were my tree, I would remove and replace.
Because I’ve experienced similar heartache, I now wrap tree trunks much higher than the protection provided by tube-type tree guards. Rolls of tree wrap are sold at garden centers, and the wrap can be interwoven between lower branches, giving a higher elevation of protection.
Q: I would like to plant a potentilla shrub this spring, but I’m wondering if there’s a reason not to. I’ve been told that potentillas used to be very common in the area, but have fallen out of favor, and you don’t see them much. Is there a reason why, and shouldn’t I plant one? – L. O.
A: I’ve got just the thing for you. Dakota Sunspot potentilla is the best cultivar of this shrub I’ve ever seen, and I like it so much, I planted a grouping of three in our own landscape five years ago.
Dakota Sunspot potentilla was developed at North Dakota State University and is a vast improvement over older potentillas. It has a compact habit, reaching a height of about three feet with a spread of three to four feet.
The neatly mounded shrub is covered with sunny yellow flowers from late spring until fall frost. When first introduced, Dakota Sunspot was described as possibly the most floriferous of all potentillas. That’s no exaggeration – the shrub is a mound of continuous bright color all summer long.
It’s true that potentillas were once more popular. Older cultivars become a mass of woody, leggy branches over time, and become unsightly if left unpruned. They can be rejuvenated by cutting back to about four inches above ground level.
Dakota Sunspot is a vast improvement, and like all potentillas, it thrives in hot, dry landscape locations. An occasional pruning every few years keeps them tidy. Dakota Sunspot potentilla is available at many locally owned garden centers.
Q: I’d like to start some of our own plants indoors from seed. Do you need to use the special seed-starting mixes I see for sale, or can I use the potting mix that I have on hand. – Shane M.
A: I use seed-starting mix for all the seedlings we grow. Such mixes are milled to be finer, and seeds are able to sprout more readily. Regular potting mixes tend to have larger particles, which could block seed emergence.
Some seed-starting mixes have small doses of fertilizer formulated to give tender seedlings just the right nutrition. Seeding mixes are usually very dry right out of the bag. The day before planned use, add water to the bag, stir well, and reclose. When ready to use, the mix will be mellow and more workable.
When seedlings are ready to transplant out of the seed-starting tray and into cell packs or pots, a regular high-quality potting mix is used.
If you have a gardening or lawn care question, email Don Kinzler, NDSU Extension-Cass County, at firstname.lastname@example.org . Questions with broad appeal may be published, so please include your name, city and state for appropriate advice.