Every spring I get asked dozens of times if tree tubes work on shrubs planted as small seedlings. Absolutely! Here’s the email I sent to a customer this morning who asked that exact question:
Yes, I have a lot of people using tubes on shrubs. Planting shrubs presents some unique challenges because most of the shrubs we plant, particularly for wildlife habitat, are particular favorites for rabbits and deer to munch on. Nanking cherries, dogwoods, American plums, etc. – all of these get HAMMERED by deer and rabbits and need protection to get started. Tubes provide excellent protection (and the added benefits of increased survival, spray protection, ability to locate the seedlings amidst the weeds, etc) but of course there is an inherent conflict between the way tubes channel growth upward and inhibit branching and the spreading form of a shrub.
There are two equally valid strategies for handling this.
1) Use 2ft tubes – The benefits are of course initial browse protection, drought protection, rodent protection, spray protection – all while minimally impacting the form of the shrub. The disadvantage is of course that deer can browse the plants as they emerge from the tops of the tubes. Often 2ft of protection is enough to get the roots established to the point where they will send shoots of growth past the deer browse line. However, sometimes deer will keep them clipped at 2ft, and you might need to double back with a deer repellent during the growth season to get them past the deer. Worst case scenario you might need to stack another 2ft or 3ft tube on top to get past the browse line. But at least you get the plants off to a safe start.
2) Use 4ft or even 5ft tubes – It sounds weird, but in some places the deer browse is so heavy you have to go this route or the deer will keep the shrubs mowed at the top of a shorter tube. For a few years you get a very odd-looking, tree-like shrub, but after the plant emerges from the tube and its stem thickens you can remove the tube and the shrub will then assume its usual spreading growth habit. Often times, once established the shrub will send up shoots from the roots outside the tube, so it also starts to spread that way.
Two ways to skin the same cat. Using 2 footers keeps costs lower and offer’s a decent chance that will be all the protection you need – but also the risk that you might need additional protection. Using tall tubes results in funny looking shrubs for a few years, but means you won’t need additional protection down the road.