Before You Plant
A little extra care on planting day will really pay off in faster growth, deep root system and a long, vigorous life. Proper planting can make a big difference between a tree that is struggling to survive and one that is thriving, so look at your time as an investment in your tree.
Before you dig be sure to check that you will not be damaging underground utilities like water, sewer, gas, and electricity Two working days before you plan to dig, mark the planting locations with a white flag or white paint (you can even use flour to mark the hole) and call the USA (Underground Service Alert, 800/227-2600 or http://www.usanorth.org/) . Your underground lines will be marked by each utility company within two business days using with flags or paint. We recommend that you do not plant trees directly over underground lines to reduce the chance of your damaging lines or your tree needing removal if the lines need replacing.
Check how wet the soil is by digging a 12″ X 12″ deep hole. If the soil is hard and dry, water thoroughly and wait a day or two for it to partially dry. This will make the soil soft enough to dig. If the soil is moist, you are ready to dig. If the soil is wet, like mud, turn off irrigation and allow to dry for a day or two and digging will be much easier.
Check your drainage and improve it if necessary. Tree roots need both air and water to thrive, soil that is constantly kept wet will actually smother the tree roots. When you dig your test hole, fill it with water and let it drain out. Then fill it again and observe how long it takes to drain. If it takes about 4-6 hours to drain, you have good drainage and you don’t need to improve it. But if water sits in the hole for 6 or more hours, you should try to improve your drainage and/or reduce the frequency of irrigation because tree roots sitting in water will die after several hours.
To improve drainage you can break up the soil around your hole, install/alter/clear drainage lines, or plant on a mound. To break up soil, you can just dig a wider hole or use a shovel or fork to “fluff” the soil up without actually digging it out. To improve drainage this fluffing needs to be done several feet around the tree hole and 15-18″ deep. This gives more places for water to penetrate.
Installing, altering or clearing drain lines may be necessary if the tree location is often is soggy or has standing water. Obviously this could turn out to be a big (and messy!) job but if it is done right, should solve your soggy soil problems. Most newer houses in Roseville have one drainage line that runs around the back yard (look for inlets in the lowest areas) and down the side yards and end near the sidewalk.
Planting on a mound is another way to provide better drainage for your tree. Mounds should be at least 9″ tall and cover as wide an area as possible. The more well-drained root area your tree has, the better and faster it will grow. In order to drain properly, construct the mound out of the soil in your garden or properly prepared fill soil. You can often build a mound from your own soil by shaving a couple of inches off from near the fence line all around the yard. If you must use fill soil, you will need to mix it with your soil to make a transition zone or water may not be able to drain from the mound to the soil. Put a 6″ layer of fill soil down and mix it thoroughly into the top 12″ of soil. Repeat until you have a mound the height you need. Do not use bags of “soil” or compost from the nursery because they are actually made from ground up woody materials and will shrink as they decay. Then what will your tree be holding on to when the mound decays?
Manage your irrigation so that water has time to soak in between waterings. Most homeowners have their irrigation set to go on every day, or even twice a day. For most soils this means the soil never dries out enough to allow air to penetrate downward. This wet soil seems to work fine for lawns with their shallow roots, but can slow the growth of trees and even kill them. We recommend that you check the moisture of your soil with an inexpensive soil moisture meter and reduce the frequency of irrigation so the soil is usually moist, not wet. Clay soils hold lots of water and you may only have to water 1-3 times a week. If you have sandy or gravelly soil, you may need to water 2-4 times a week.Your plants will thank you if you make irrigation changes slowly so they can grow deeper roots. Consider adding a day between waterings when you turn your system on in the spring. Check with your moisture meter that the soil is “moist” and run your irrigation again when it is getting close to “dry”. This will help your trees to develop deep roots and faster growth.