Caring for winter damaged trees

Frozen BranchesWinter storms and arctic cold events can be damaging to trees and shrubs. Remember to inspect your plants for broken limbs or lodging over in soppy wet soils after storms. Make clean cuts when you find broken, torn, or split limbs. Clean cuts will be less susceptible to fungal infection than ragged breaks.

If you have lost the top of a more recently planted tree you may be able to train a new top for it. If the break occurred above the graft, and above a flexible side shoot, you can train that shoot to be the new leader with a splint. Make a clean diagonal cut ¼” above the side shoot, tie a piece of bamboo or other stiff material to the trunk in two places below the shoot, then carefully bend the shoot upwards and tie it to the bamboo in two places, to create a new top on the tree. If there is no flexible side shoot available, but the break is above the graft, make a clean diagonal cut ¼” above a bud or node, and cut back any non-flexible side shoots within 6” of your cut to one or two buds. In the spring after the new growth is out about 6”, select the strongest most vertical shoot, remove the others, and splint as necessary to keep the shoot straight.

Sometimes newer trees break off at the graft or below, in that case there is not much you can do. All you have remaining is the rootstock, which you can either allow to grow a new top to graft onto, or remove and replace with a new tree.

If your tree has developed a strong lean, or has fallen over, you may be able to help it re-establish its upright habit again. If the roots did not come out of the ground, place a prop against the trunk or under a sturdy limb and push the trunk straighter. A big lean may need to be pushed back up in smaller increments, to avoid causing any further root damage. Sometimes snow weight puts a bend in the tree. If the trunk is not too thick you may be able to push it back up straight. The tree will need help to stay upright, secure a sturdy metal rod or 2x piece of wood to it. Tie the splint to the tree in two to three places below the bend, and within and above the bend so the splint holds well. Keep the splint on for at least one growing season.

If the tree has leaned almost to the ground, or completely fallen over, most likely the roots on the opposite side have either broken off or pulled out of the ground. Before trying to straighten the tree dig under the roots on the opposite side to make a hole the roots can settle back into when you push the tree back up. Cover the roots with soil after you have righted the tree. To balance the top of the tree with the root damage it is best to prune the top of the tree also, up to 50% of the top of the tree if there was a lot of root damage. Make more thinning cuts than heading cuts, leaving as many terminal buds as you can which will send the message to start growing to the roots in the spring. Stake the tree, using 2-3 stakes, protect the trunk with rubber strips (or something similar). Leave the tree loose enough to be able to move an inch or so in any direction, but not much more. Remove the stakes after one season if the roots were not broken, after 2-3 seasons if there was a lot of root breakage (to give the root system time to fully re-establish).


Tips on winter storage and release of Mason Bees

Mason beeWe plan to ship mason bees mid-January through the end of February, weather permitting. When you receive your bees they need to be kept cool until you are ready to release them. Keep them in the refrigerator at 36-39° F. It is important to maintain proper humidity for the bees in a frost free refrigerator. Poke several small holes in a plastic bag, put the cardboard box of cocoons inside that bag along with a barely moist paper towel, close the bag, and put it in the refrigerator.  In addition to the Mason Bees we also offer the Green Raspberry Bees. These are similiar to the Mason Bees but they fly later in the season and are the best pollinators for berries and other fruits that flower later in the season.          

Mason bees will emerge naturallyin response to warming spring temperatures, if you set up the nest box and release box (with cocoons inside) as soon as you receive them. They will survive short periods of exposure to temperatures below zero, but if you expect you will have long periods of sub-freezing weather it will be best to store the bees in the refrigerator until winter has moderated. If you store your bees in the refrigerator you can time the release of your bees to coincide with the bloom time of trees, or groups of trees, in your orchard. If you are just starting a population, you will need to release all of your bees at the same time. Wait to release them until you see flower buds in your orchard beginning to swell, or about 3 weeks before the flowers open.

Place the straws filled with cocoons in the release box you purchased with your straws of bees. The Royal Bee House #T332 also has room for the straws. The bees prefer to emerge from a small dark hole into the rising sun to the east, stepping out onto a small platform they can get their bearings from before they take flight. The hole needs to be above the bottom of the release box, and the same diameter as the straws or tubes in your nest box. Locate the release box near the new nest box the bees will use, so they know where to find it.

You can maximize the pollination potential of your mason bees by releasing them just prior to the bloom of each of your major fruit bloom seasons. Store them in the refrigerator at 36-39° F as soon as you receive them, or right after you clean your established population in the fall (see October Growing Tips for more on cleaning). Keep the bees well cushioned (on a pile of toilet paper, for example) in a container that is porous, so they can breath. Then follow the directions above for keeping them in optimal condition in the refrigerator.

Put a quantity of bees in a release box as each type of fruit is preparing to bloom, or about every 6 weeks. Margriet Dogterom’s book “Pollination with Mason Bees 2ndEdition’ #S427 has instructions on making release boxes from a tin can or cardboard box if you do not have enough release boxes. Be sure to have new, clean places for your bees to deposit their eggs into when they emerge, although it will be a few days before they are ready to use them. Either insert new clean straws in the Calm Bee Nation blocks you used last year, or set out Bee Diverse Stacked Trays you cleaned last fall after removing and storing the bees.


Planting tips for our customers in the deep South

If you are in one of those southern sunny locations where the optimal planting time is before we are able to begin shipping to you, you may need to take special care with your plants when you do receive them. Please see our Plant Owner’s Manual, pg 10, for late planting instructions or the following:

1.If you choose to plant out in a permanent location right away and your day time temperatures are in the mid-70’s or higher; mulch the soil surface well after planting, irrigate regularly to keep the soil evenly moist, not soppy wet, and provide shade until the plants are well-established. Warmer air temperatures encourage faster leaf and shoot growth than root growth, creating an imbalance between supply and demand in the plant. Shade helps to reduce the water needs of the plant and give the root system time to grow and catch up with the water demands of the top of the plant.

2.Plant your new plants in a temporary, shady location, mulch, and water regularly through the summer. In the fall, when the worst of the summer heat has passed, move the plants to their permanent location. By the following spring they will be well-established and ready to perform.

3.Plant your new plants in containers, or if you received potted plants put them in a somewhat larger container. Maintain them in a protected location, and plant in their permanent location in the fall when the worst of the summer heat has passed.


Planting tips for gardeners in warm and maritime climate areas

Planting of potted and bare root stock can begin in January in moderate winter climate locations. In some southern areas January is the best month for planting. West of the Cascade Mountains in the Pacific Northwest, so long as the ground is not under water or water-logged, frozen, or covered with snow, you can go ahead and plant. Planting at this time is almost as good as planting in the fall, roots have plenty of time to dig in and establish before the tops of the plants start demanding water and nutrients in the spring. Be sure to read the Owners Manual we send with your new plants for specific planting instructions.

We ship to California and Arizona in early February but we can’t ship to the Southeast until early March because plants in transit could be damaged while crossing the frigid Rocky Mountains.


How to determine which plants will work in your location

Along with understanding temperature patterns in your area, it is also important to determine how much and for how long daily your plant will receive sun in a particular location.

Fruiting trees, such as apple, pear, and plum, initiate new flower buds for the next spring season between late June and early August, depending on your location. Typically, a minimum of eight hours of direct sun daily are needed during the blossom initiation period, for maximum flower bud potential. Blueberries are fine with a minimum of six hours. Your plants may still thrive and grow with fewer hours of direct sun during the blossom initiation period, but the next year’s fruit production will probably be reduced.

How much root and branch room is in that spot I want to put a plant in?

Find out how tall and wide the plant you are interested in is expected to grow to, and make sure it will fit where you intend to put it. We put expected managed height and width (not maximum) for most of the plants in the Raintree Nursery catalog. Look for the outlined box with Useful Facts or the main plant description. You’ll find the information online on our Plant Care page. If you do not currently have a catalog, you may download a copy here.

We recommend Pruning & Training Revised by Christopher Brickell and David Joyce for more information about pruning.

With pruning you should be able to hold a tree comfortably to 75% of its potential — any smaller and you will be in constant battle with it. There are pruning techniques that do allow you to keep a tree significantly smaller, if you are diligent and attend to them regularly. See Pruning and Training-Revised by Brickell and Joyce for instructions. If you have a space that is long and narrow, there are some options for you, such as a hedge of blueberries or blackberries, or you could train a fruit tree as an espalier.

Why soils are important

It is also valuable to know what your soil is like, such as heavy clay, sandy, high or low level of organic matter, pH, soil depth, and nutrient levels. Have your soil tested professionally (ask your local co-operative extension office for recommendations in your area), or explore it yourself. Wet soil that is high in clay tends to be sticky, silt soils tend to feel smooth, and sandy soils tend to feel gritty. Organic matter tends to darken the color of the soil, bind a sandy soil, or lighten a clay soil. A simple test kit (such as the Rapitest Soil Tester) will help you determine the pH and primary nutrient levels in your soil (nitrogen [N], phosphorous [P], and potassium [K]).

Different plants evolved, or have been selected to perform best, in specific soil conditions. A cactus planted in heavy wet clay would start suffocating from lack of oxygen to the roots immediately; an acid loving blueberry planted in typical garden soil pH of 6.5-6.8 would be unable to absorb nutrients, leading to unhealthy yellow or red foliage color, lack of vigor, and eventual death. An apple tree planted in a soil with pH below 6, that tends to hold a lot of water in winter and spring, and does not have much depth above a hard-packed subsoil will tend to just sit there, or die, because the root system is in such a hostile location. A blueberry planted in the same location may thrive.

Rapitest Soil Tester
The Rapitest Soil Tester will help you determine the pH and primary nutrient levels in your soil.
For most soils, the best modification for the soil structure is to add organic matter. Clay soils benefit from straw or leaves piled on the surface and allowed to decompose. Sandy soils benefit from any balanced compost or organic material applied to the surface and mixed in over the entire planting area, or better yet, expected root zone area, before digging the planting hole.

Nutrient and pH issues are corrected with amendments (lime or sulfur to correct pH, and fertilizers). Avoid affecting only the planting hole, tree roots in particular are eager to spread out and establish. Adding amendments to a broader area encourages actively spreading root growth, and therefore stronger top growth.