A tight - growing shade tree , river birch(Betula nigra ) is the most wide adapted of the birch rod trees . It is hardy in U.S. Department of Agricultureplant hardiness zone 4 through 9a . In USDA zona 8b and 9a , river birch needs regular irrigation to survive the heat .
Preferred Conditions
Since river birches can contact 40 to 50 foot tall and 20 to 30 feet broad , they take raft of elbow room to grow . Space them 15 to 20 base apart and at least that far from hardscape elements . Avoid implant them in shallow land in USDA geographical zone 8b and 9a , so they can establish deep root systems to survive the heat .
River birchgrows good in full Lord’s Day , but tolerates partial spook . The tree will acquire in a more overt shape if planted in the shade . The drooping branch can be messy , so do n’t imbed them close to high - traffic areas unless you want to pick up after the tree diagram and prune them on a regular basis .
As the name implies , river birches prefer damp soil . Once found , however , they will suffer ironical soils . Theygrow well in acid soils , and spring up iron deficiency in filth with a pH higher than 6.5 . This high predisposition to alkaline dirt mean you should quiz your soil before planting river birch to check that the stain is safe .
Soil Amendments
Adding constituent topic to the soil before planting will ameliorate the grain and increase the stain ’s power to hold water . Composts are a familiar amendment , but they are often slenderly alkalic . Unless your soil is already acidulous , do n’t use compost when amending stain for river birch . * * sphagnum moss peat moss is a much good choice than compost , * * since it has an acidic pH.
disperse the peat moss 4 inches thick over the land aerofoil where you will be planting . conflate it into the soil to a depth of 8 to 12 in . If potential , amend and till the territory in an area two to three times the size of the hole you ’ll be digging to plant the birch rod Sir Herbert Beerbohm Tree .
If a soil test designate the pH is too high for river birch , applyinggranular sulfur is an alternative to amending with peat moss . If the current pH is 8.0 , practice 0.3 to 0.4 pound of coarse-grained sulphur per 10 square metrical unit . For dirt with a pH of 7.0 , implement 0.1 to 0.2 pounds . If you ’re applying more than 0.2 pound sterling per 10 square foot , spread this out over two applications three months apart . This is best done a twelvemonth before plant the tree .
How to Plant
flora in the recent winter or early leaping , just before new growth begin and after soil temperatures are high than 45 degrees Fahrenheit . hollow a pickle 2 to 3 clock time the size of it of the container or root lump . Make the hollow the same depth as the roots , so after planting the tree sits in the soil at the same depth that it was grow previously .
If the works is balled and burlaped , mark the whole root clump in the muddle without removing the burlap . Fill in about three - quarter of the muddle . relax burlap and fold it back so the top of the root ball is let on . move out any wire that was holding the top of the burlap . Finish fill the hole .
For container - grown plants , remove the tree from the passel . Use a pruning knife or shears to contract any large roots that completely circle the rootage globe , and undo the smaller roots by hand . Set the plant in the hole and fill in around the root clod . If the container is biodegradable , tear off any part of the raft that run above the soil horizontal surface and cut five or six slashes in the side of the pot with a service program knife , then plant the entire thing . Before habit , disinfect any cutting pecker by soaking them in a mixture of 1 part bleach to 3 parts water system for 5 minutes , then uprise them with clean piddle .
After Planting
water enough to keep the source testicle moist after planting is cardinal . To help keep the water near the tooth root glob , build a ring of soil 6 to 8 in from the boundary of the hole . fill up this anchor ring every time you irrigate . The ring should be smoothed into the dirt by the last of the second growing season .
For works that were grown in containers , plan on watering two or three time a calendar week for the first few weeks . plant that were ball and burlaped typically have roots surrounded by a water - retentive soil and only need water once a week .
Avoid over lachrymation by checking the stain wet before watering . If it still feels pie-eyed , do n’t irrigate . About1 inch of pee per weekis a honorable guide , perhaps more in peculiarly hot weather .
