Rhododendron roots
nhmom2four
14 years ago
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diggingthedirt
14 years agoctlady_gw
14 years agoRelated Discussions
Is my rhododendron root bound? Help!
Comments (2)This is a common occurence for rhododendrons grown in pots with a peat based planting medium. What you did already is exactly right - tearing off pieces often happens and will do no harm. If the root ball is very dense, slicing it in several places along the perimeter and across the bottom with a sharp knife is also a good idea. A hand cutivator with sharp prongs and/or a forceful stream of water from a hose can also be used to loosen the roots. Soak in water for a half an hour or so before replanting. Then - and this is important - water when needed with just a very slow trickle at the base of the plant for the rest of the summer and fall. You want to keep the root ball moist without saturating the surrounding soil. You might also want to check your planting area. You want a wide shallow area amended with lots of organic matter - if there is an abrupt transition between the planting medium around the roots and the native soil, it's very difficult for the rhododendron to extend its roots....See MoreRhododendron Root Weevils Plus Grubs
Comments (1)Dax, the weevils may, or may not, be the reason for your die back... But there are things you can do to control them. Don't let low lying branches act as a bridge from the ground, prune up anything touching soil. Hand pick adults (night, with flashlight)....I have to admit this isn't my favorite insect to pick by hand, something about the crunch factor when squashing them. Give beneficial nematodes (like Biosafe) a try for the larvae. I think the recommendation is when soils reach 50F, here they may be most effective in Fall after it starts raining but certainly worth a try. The adults are easily killed with a foliar spray of systemic Orthene...I prefer not to use Orthene until after flowering to protect bees. Here is a link that might be useful: Weevil control...See MoreIs my Rhododendron root rotted?
Comments (3)Rhododendron roots are very fine and hair-like. The thick white roots you're seeing are almost certainly from the tree. They have made their way into the moist peaty area over time and are taking up all the available water and nutrients. This is causing the rhododendron to wilt because it is simply unable to get enough water. The first and last photos do show some reasonably healthy green leaves on the rhododendron, so the rhododendron root system has not rotted away. A few of the middle photos - the second one from the top especially - do show branches that look extremely desiccated. Branch dieback is fairly common in rhododendrons, especially in those experiencing stress from too little or too much water. There's no way to tell from a photograph if this is the case or if it is just from extreme dryness. Best thing you can do is dig up the rhododendron, soak the root ball in water for 30 minutes or so and replant. (Should the rhododendron roots appear moist when you dig them up, then I'm wrong and you probably do have some sort of fungal infection preventing water uptake. I'm betting, however, that they will be dust dry and entangled with lots of tree roots.) Growing rhododendrons in the shade of trees, especially maples and other species with aggressive roots, is a challenge. Avoid peat which becomes very hard to rewet when it dries and use bark instead. Water the rhododendron with just a trickle from a hose at its base. You can try cutting around the rhododendron with a sharp spade two or three times a year to sever the tree roots but this is never very successful in my experience. Once the rhododendron has grown a larger root mass, it can compete with the tree roots, but until then it will need a lot of TLC. There is a very well done discussion of growing rhododendrons under trees at the Singing Tree Gardens website if you're interested....See MoreCalculating Rhododendron Root Diameter
Comments (0)Are there any good rules about calculating the diameter of a rhododendron root system? I do understand that these roots will not go down vertically more than about 12 inches. They do spread out horizontally near the surface. I need to size a container to the predicted adult size of the plant, so I need a guideline on the root size, based on height or width of the part of the plant that is above the ground. In a related question, what happens to a rhododendron if the planter is too small? Will it just reduce its growth? Can rhododendrons be raised in a bonsai fashion and ultimately end up being miniature versions of the normal plant?...See Morestill_lynnski
14 years agodiggerdee zone 6 CT
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14 years agonhmom2four
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14 years agodiggerdee zone 6 CT
14 years agonhmom2four
14 years ago
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