Q. Why don’t I dig a huge hole (several times the depth and width) of my new tree’s root-ball?
A. Old-school thinking on this topic was that trees needed a good start in life and should be planted in perfect soil. A hole was often several times the width and depth of the root-ball. This theory sounds good and could even work if you dug a hole big enough to contain the tree’s root system when it’s full grown. Unfortunately this isn’t practical for most situations. Several studies have shown that trees planted in perfect soil run into difficulty when their roots grow past the perfect soil and reach the imperfect soil. If the soil they come into contact with contains a fair amount of clay (as do nearly all of the soils in our area) then the roots will tend to look for an easier place to expand to. Roots will either turn back and expand into the soil you provided them or they may start to circle around the current root area (girdling) looking for an easier way into the less than perfect soil. When this happens the tree will be unable to find new sources of moisture and nutrient and it will languish. A tree in this state is highly susceptible to diseases and insects.
High winds can also cause a tree in this condition to blow over. If you picture a tree sitting in a large bowl (the big whole you dug) then you may begin to see how this can happen. A tree planted in a hole using the original soil gets used to the growing conditions for the area right away. It may not put on quite as much growth initially but will be a more reliable and vigorous grower in the future. There are occasions when it could be beneficial to make minor additions to the soil. For information on amending soil click here.
Q. What are Mycorrhizal fungi and why might my plant benefit from them?
A. Mycorrhizal fungi ( www.usemyke.com) are naturally occurring fungi which attach themselves to the roots of plants and form a symbiotic relationship with those plants. In exchange for a small percentage of the plants’ production these root colonizing fungi protect plants from other fungi which might attack the roots or attack through the roots. By forming a network of filaments which extend far beyond the normal root range of a plant these fungi also give the plant access to greater amounts of nutrients and moisture. Some of the benefits of this are improved rooting and faster establishment of newly planted plants. This results in an increased tolerance to adverse growing conditions and decreases the amount and frequency of watering required to establish a plant. You should also be aware that not all plants can be colonized by mycorrhizae and that when you are planting in undisturbed soil (generally near an older home where synthetic fertilizers haven’t been used) within a year or two your plant will very likely be colonized by locally occurring mycorrhizae.
There is some question as to whether or not locally occurring mycorrhizae (which are genetically similar to but not likely identical to the purchased product) may be better suited to colonize your plant in the long run. As with so many things in our natural world this has not been well studied but is another theory that sounds plausible. You should also be aware that mycorrhizal fungi are adversely affected by synthetic fertilizers containing phosphorus. Just another good reason to avoid synthetic and to use organic fertilizers! If mycorrhizae have been killed off in the area where you are planting then they can take years to re-establish.
Q. When I look at the root-ball of my plant I see roots growing in a circular fashion around it.
A. Your plant is girdling. If left unchecked this can kill it. The easiest solution is to take a box-cutter knife and set it to about1/2” (1.25 millimeters) and slice these roots off. If these roots are ¼” or smaller then there will be no long term consequences to the plant. (if you are replacing a plant that died in the same spot then you should consult an expert to learn why it died and find out if you should be concerned that your ground contains a pathogen such as verticillium wilt. In that case you should wait long enough for the new cuts to seal themselves before planting or pick another spot (phone or email email@example.com for information on your specific tree type)).
Some types of slow-rooting girdled plants with several roots larger than ½” are at serious risk of dying or experiencing major dieback within a few years. Examples would be Oaks, Ginkgos and Crimson Sentry Norway Maples. Not likely at risk would be vigorous growers such as anything in the rose family (fruit trees, Choke Cherries, Mountain Ash) and Silver/Red Maple crosses (Acer fremanii) such as Autumn Blaze and Autumn Fantasy.
Regardless you should talk to the place where you bought it and see what they say. Girdling occurs when a plant has been in the pot too long. Some plants can root out to the edges of the pot (where you want them to be for transplanting) within 6 weeks and start to girdle within a few months. Most plants take a year to root properly and another year before they start to girdle. A few plants take 2 years to root and several more years to girdle. Most plants can be girdled in the pot for at least a year before there is a serious risk of post-planting problems. Plants in pots show symptoms of girdling in late spring (poor leafing out) and (more often) summer (leaves will droop even when root-ball is well soaked – an otherwise healthy plant receiving too much water for an extended period will also have droopy leaves).
Q. Why should I bleach a pot before I re-use it?
A. Soaking a pot in a bleach solution (10% bleach, 90% water) for 20 seconds (clean pot) or more (45 seconds for a dirty but not caked-on pot) will kill almost all of the possible plant pathogens (plant attacking fungi, bacteria and mycoplasma). This gives your new plants a leg-up when they are going through the stressful period of adjusting to a new environment (your pot). I am always amazed at the customers who plant in last years’ potting soil or re-use a dirty pot and are surprised when their plants have problems. Containers don’t contain a complete ecosystem where everything is in balance and where plant pathogens are attacked by their naturally occurring enemies. Organic potting soils can help somewhat to keep things in balance but most containers have a sterilized potting soil and the best place for it when the year is done is in your composter or your garden.
Q. I have purchased a plant in a fibre pot (made from compressed peat moss, coconut fibre, etc.). How do I plant it?
A. All garden plants like to be free of their pots when they are planted. Having said that, often when you buy a plant in a fibre pot you have to balance the need of the plant to grow and expand over the course of the next few years with the need of the plant’s roots to be disturbed as little as possible during transplanting. There are several reason why plants are grown in fibre pots. Some garden centres sell recently potted plants where a bare-root (usually dug the previous fall with the soil removed) plant has been placed in the pot in fresh soil (also often contains bark and peatmoss). These plants have insufficient roots and cannot be removed from the pot without damaging what few roots they have. Garden centres (definitely not Make It Green!) sell these plants expecting their customers to plant them in the ground, pot and all (although judging by the number of complaints we hear, this instruction doesn’t always get passed on to the customer).
Other plants have been field dug and placed in fibre pots because of concern that they would suffer too much root damage if they were transplanted again before they had a chance to grow new roots. Some plants such as Daphnes are very sensitive to transplanting and are sold in fibre pots to allow them to be installed in as gentle a fashion as possible. Roses are often grown in fibre pots to allow sale of them before they have completely rooted in the spring (it takes 6 to 8 weeks from transplanting for a rose to root). In all the above cases unless you have reason to believe that the plant in question has had enough time to thoroughly root you should place the plant in the hole, pot and all, and once in the hole gently slice six or eight slits in a vertical direction on the sides of the pot. Even if your slits don’t go all the way through the pot you will speed up the decomposition of the fibre and its eventual incorporation into the surrounding soil. Once you have filled in the hole, the rim around the pot should be cut or peeled off to ground level, in order to keep the plants’ soil level and moisture more consistent. If you have reason to believe that your purchase has been in the pot long enough to root properly then you can treat it as container grown and remove the pot completely. It is a very good idea to ask questions before you buy any plant in this type of pot.
Q. I have purchased a tree, large shrub or large evergreen in a (burlap and) wire basket. How do I plant it?
A. Before you read these instructions you should be aware that you need to be in reasonably good shape to plant a wire-basket sized tree and that these trees can weigh several hundred pounds (or kilos). Unless you are a keen do-it-yourselfer planting these beasties is best done by professionals. Unfortunately, many of the so called professionals, especially those involved with new home construction landscaping, do a slipshod job when it comes to planting these trees. Knowing how it should be done may help you to make sure they do a proper job.
Larger trees and evergreens are often available only in wire baskets. A wire basket is a root holding device made from steel and the containing of the soil of the rootball is aided with burlap and rope. The tree is dug from the ground (generally in spring but fall is possible) and the roots are trimmed to fit inside the space provided by the wire basket. When planting a wire basket plant it is generally best to remove the wire basket unless you have concerns that the rootball’s soil is sandy and may fall off the roots when the basket is removed (in which case you can ignore the rest of the instructions about removing the basket or you can remove as much as you feel is safe).
The first step is to maneuver the tree within a foot or two of the hole.
Next you should remove the portion of the basket that is under the rootball (it’s easier to do this now then when it’s in the hole). The best tool we have found for this job is a set of bolt cutters but failing that a hacksaw will do if you are careful not to cut into the rootball.
Next you need to maneuver the tree into the hole. If you are not using equipment then this is best done by rolling the tree into the hole. An ideal way to do this is to roll the tree nearly to the edge of the hole and then have two (or sometimes more depending on just how big a monster you bought) people roll the rootball into the hole while a third person holds the trunk of the tree to try and keep it upright – heavy trees (especially evergreens) are easier to move into the correct place before they are stuck at the wrong angle in a hole! When you are rolling it into the hole aim for the edge of the hole, not the middle. You will find that the tree (and you) will have a much easier time during entry and will still wind up in the middle of the hole. It is possible with a little physics and foresight to determine exactly how the tree will lie after it is in the hole and to change your angle of entry to place it exactly where you want it (it gets easier with practice).
Once the tree is in the hole and placed exactly where you want it then you need to remove the rest of the basket. The burlap surrounding the rootball can be left in place although it is best to roll back the top portion of the burlap to the sides of the rootball (it will rot in place in a few short years and add to your soil’s organic matter).
In order to roll this back you will need to untie or carefully cut away the rope which has been used to tie the burlap to the trunk of the tree. Failure to do this will likely result in the death of the tree in the next 10 years or so. This rope will choke the trunk and cause a weak point which, among other possibilities can cause the tree to break off at that point in a high wind. Many, many, many of our customers have discovered this on their trees planted by their home builder or landscape contractor. (This despicable slipshod practice is not only detrimental to the environment by causing needless tree deaths it also undermines consumer confidence in their own ability to care for plants which is a major reason people give when asked why they don’t buy plants). Although we won’t mind selling you a tree in 10 years we would rather have you check for this on your current trees. Once you have removed the basket and rope you can continue to plant following the standard planting instructions. One other point about large, heavy trees is that if you have a recently (last 5 years) graded lot then it is possible that these bigger trees may settle and imperative that you Plant Them a Few Inches High. Under these circumstances it is also likely a good idea to Stake Your Tree.
Q. My wire basket plant appears to be surrounded by plastic instead of burlap. How should I plant it?
A. Congratulations! You have purchased a container grown wire basket tree. These trees were not recently dug and stuck in this basket, they have grown there for long enough to properly root and will continue to grow as soon as you plant them in the ground. Since this type of wire basket tree weighs much less than the dug kind you will likely be able to first lift it into the hole (with two people) and then remove the wire, rope and plastic. These trees are less likely to sink in newly graded soil and less likely to require staking.
Q. My plant’s rootball is surrounded by burlap but no wire or I just took my plant out of its pot and the rootball is surrounded by burlap. How should I plant it?
A. If the rootball has no rope around it then just plant it, burlap and all, being careful to not plant too deeply (if it does have a rope then remove the rope from around the trunk first). The burlap should be rolled back from the top part of the rootball and buried. Some plants with this type of rootball can be quite heavy and may sink in newer soil and thus are good candidates for planting a few inches high. A rope around this sort of plant may be used to help hold the rootball together, especially if the plant was grown in sandy soil, or it may simply have been added to make transportation of the plant easier. If it looks like the soil may be loose then you should leave the rope in place (except where it contacts the trunk or branches), otherwise remove it.
Q. I have just built a new garden bed or recently filled in or graded a section of my yard. Do I have to follow any additional planting instructions?
A. Yes. Thanks for asking as this will save the lives of your plants! Recently graded areas (this can be anytime in the last five years although in most cases it only takes two or three years for the ground to settle) have less dense soil than normal and will settle over time. Any plant that you plant in this fluffy ground will sink because it is heavier than the surrounding soil. In the not-to-distant future your plant will be deeper than is safe for it. If this is a new garden bed then you can have the same problem. It’s not just sinking plants you need to worry about its also new soil being washed onto your plants by rain or sprinklers. Although some plants can adapt very easily to these changes and some plants can adjust given enough time, they may still be at greater risk of contracting diseases down the road. If soil touches areas which don’t have the full benefit of the plants natural underground protection it can convey or encourage pathogens (primarily diseases which can more easily attack the plant under the moist and dirty conditions). Most new garden soils will settle one inch in four – if it’s a foot deep when you create it, it will only be nine inches deep after a couple years – the trouble is an eight inch deep pot (12-8=4 inches of new soil underneath) will settle one inch in a matter of weeks or even days if it rains or you water enough and that inch can be deadly. Evergreens are particularly susceptible to death by suffocation with as little as ½” of soil over the rootball. If you can wait a few weeks (and rainstorms or waterings) after you have built your new beds, and then plant, you will avoid most settling issues. If you just can’t wait then plant an extra inch (or more) high for every 3” of soil under your new plant’s rootball. It never hurts to check the plant’s soil depth for the first few months.
Q. I dug my hole too deeply. What now?
A. You will have to fill in the hole to the proper depth for your plant’s rootball and then add an extra inch of soil for every three inches you had to fill in. This allows for settling. It won’t hurt to water this soil very well before planting as it will start the settling process. Please read the sections on Planting In New Soil and Staking.
Q. What do I need to be aware of when planting on a slope?
A. Planting on a slope provides special challenges both during and after planting. Sloped terrain tends to be dry since surface water drains away very easily. Amending your soil with compost can help alleviate this problem somewhat. Choosing plants which like it dry is also helpful. If there is any reason to expect some soil erosion then you should check your plant root zones from time to time and make sure that soil is not accumulating and causing your plants to suffocate. The challenge with the planting process is to determine just how to place a plant which has been grown on a level surface into a hole dug into a slanted surface. One solution, if it’s doable is to terrace the slope so that you have level areas. Then you can plant normally.
If you can’t terrace then you have two choices. You can dig your hole straight down, ignoring the slope and dig it deeply enough to plant the top of the rootball such that the centre is at the same level (or slightly above) as the surrounding slope. A plant planted like this will often suffer somewhat on the uphill side until the roots adjust to the slope by growing up to fill in the soil which will accumulate there. The portion of the plant on the lower side will tend to dry out easily but if you keep it adequately watered then it will help the high side stay alive long enough to re-root.
The other option is to dig your hole perpendicular to the slope and plant your plants at an angle. Although this will work well for annuals, perennials and some shrubs (spreading junipers, any shrub that will look good when it curves towards the sun) it is not usually recommended for trees or large evergreens. Trees and large evergreens planted on slopes will often require staking.
Q. I think I will be building up the soil (at some future date) in the area where I want to plant this plant. How should I plant it?
A. Figure out how much soil you want to add and plant your plant as if that soil was already in place. Planting high is a common practice in areas of poor drainage or wet soils and will not hurt your plant as long as at least half of the rootball is in the ground. If a lot of the rootball is exposed then it may be a good idea to mulch it and remove the mulch before you plant. Don’t wait too long! A few years should be fine but if your plant gets well rooted and starts to grow well it will spread roots into the surrounding area and may be unhappy when you cover them up with new soil.
Q. What do I need to add to my soil when I plant a tree in my lawn?
A. Very little. You should add some bonemeal and some mycorrhizal to encourage root growth. If you are concerned that your soil is dense clay or sand then you could add compost to help with drainage for clay and moisture retention for sand. This would depend on the type of trees chosen. A willow wouldn’t care if you gave it better drainage, a Caragana wouldn’t be to impressed by better moisture retention in sandy soils. If you switch their locations around then they would be very appreciative (they may survive now but they would have a difficult time of it). Having said that, the vast majority of middle-of-the road requirement trees would appreciate this sort of amendment. The most important thing to be aware of when planting (especially in clay) is to make certain that you don’t change the soil in the area around the new plant too much so that it will root into the undisturbed soil without difficulty.
Q. What can I add to my soil to make it better?
A. Many people, especially in the Ottawa area, seem to think that they have to dig out and replace all of the soil when they want to make gardens. Some of this probably comes from their experiences with the soil that builders have left in their yards. The existing soil is generally two inches of topsoil (when 8 would be great) over clay. If you are lucky then it is the original clay from the building site. If you are unlucky then the clay layer has been made up of fill, from digging out basements, then mixed with rocks, rocks and more rocks from blasting out basements (through in a few pounds of nails, particleboard and paint cans and you have it about right!). This clay/rock combo has much less nutrient in it than original clay and can be quite difficult to work with.
Given enough patience even it can be turned into nice workable soil. To break the clay up and make it workable there is one easy solution; compost and lots of it. Unfortunately it can take several years to create a great garden bed using this method. You will generally need to add two inches of compost in the first year and one inch of compost each year thereafter for the next six or seven years. There are some products on the market which are supposed to help you do this more quickly and we are currently evaluating another one, but so far we haven’t found one that works better than compost.
Too much compost can introduce excessive amounts of nutrients to your soil and may cause plants to grow leaves at a phenomenal rate while producing little or no fruit or may cause a tree or shrub to continue to produce new growth when it should be shutting down for the year and hardening off for the winter.
When you plant a tree or shrub in clay you can mix some compost with the original soil (a good rate is ½ a rounded shovelful per gallon of pot – the size is usually listed on the tree tag or on the bottom of the pot – sizes may be listed in cubic centimeters – dividing by 400 will give you a good approximation of pot size). If you are worried about drainage then you should consider planting a few inches high. To reduce the potential for ‘over-composting’ you could add peatmoss or any other nutrient poor organic matter such as coconut husks, rice fibre and a whole host of other products being introduced at a rapid rate. Each of these carries an environmental cost and may have detrimental properties (as well as beneficial). In the future we will be evaluating each of these products and presenting our findings on the website. One word of warning: clay soil should never be worked when it is wet (sticks together and allows you to form it into a ball). The soil structure can be badly damaged and take decades to recover. When adding compost there is no need to work it in – just add it to the top and Mother Nature will work it in for you.
Q. Should I mulch my tree/garden?
A. Like so many questions that come up when you are dealing with live, complex plants this one doesn’t have a simple answer. If you are planting in the spring then you should only mulch to protect the plant against drying out or weed growth. Some plants like it on the dry side and mulch can be quite detrimental to their health if they are also getting regular watering (including rainfall). Most plants will appreciate a one or two inch layer of mulch. Using too much mulch can give the same effect as planting too deeply so don’t overdo it.
Recently planted trees (less than two years) will usually appreciate an application of mulch in the fall (try not to touch the trunk with the mulch). This allows them to grow new roots longer into the fall and early winter than otherwise (yes, they are still growing even when they are dormant above ground). If you remove this mulch as soon as possible in the spring then they may be able to do a bit more root growth before they leaf out (this generally only applies to a fall planted tree in it’s first spring) and the soil around their roots will lose the excess moisture present after the snow melts. A new tree will only grow roots based on its stored energy level so if you have a long fall then mulching might not make any difference. There are many different kinds of mulch (we carry southern pine bark, cedar, composted pine, cocoa shell and many types of decorative stone) and each have unique properties. In some cases it is better to use a landscape fabric between the soil and the mulch. When it comes to mulches there are few apples to apples comparisons – pine bark from the southern states resists decay much longer than its northern cousins; some colouring processes used for cedar mulch are better than others (stick your hand in the bag and it should come out without any colour on it!). Unfortunately it can be hard to tell which one you are buying. In the future we will publish a section on the many different types of mulch and their applications.
Q. When should I stake a tree and how do I do it?
A. Old school thinking said that every tree should be staked for two or three years to allow it time to get properly rooted. Like so many things, this theory sounds good. It has probably persisted as common practice much longer than it should have because of the ‘my neighbor told me so’ syndrome – a topic for another time! A stake on a tree is like a crutch. If you have ever been on crutches then you know how weak your leg is when you can finally stop using them. The trunk of your tree feels the same way. When staked, a tree does not develop as strong a trunk as it should. I have seen trees topple over when the stake is removed. The toppling can occur as a result of a high wind or it can occur in late fall/early winter when the sap has retreated from the trunk into the roots and the trunk looses some of its rigidity. Still, there are times when trees will benefit from being staked. There is a tradeoff between root growth and trunk strength. If the tree won’t stay relatively still then it may have a hard time rooting.
If your tree is in a very windy location, on a slope of 30 degrees or more or on ground which will likely settle then it is generally a good idea to stake. The number of stakes to use depends on the type of situation you find. Trees planted on unstable ground (not something that we would recommend!) will fair best with three stakes placed at equal intervals around the tree. You can get away with two stakes most of the time but if the area that settles is half way around the tree from each stake then your tree can still tilt. Trees in windy or sloping locations generally only require one stake in the prevailing wind or slope direction (upwind or upslope). If it is windy and sloping then you can use a stake on the upslope side and a stake for the prevailing wind. There are many ways you can attach a stake to a tree and every garden centre should have several methods for you to choose from. Please don’t use rope or twine, string, bare wire, aircraft cable or chain (we’ve seen them all and the damage they do to the trunk). The lower you attach your stake to the tree the stronger the trunk above that point will grow (sort of a compromise between root stability and letting the tree move as much as possible). Although each tree is unique (columnar type trees can be staked lower than globe shaped, for instance) a good rule of thumb is somewhere between 1/5 and 1/3 of the tree’s height when planted. Taking the stakes off at the right time can minimize side effects such as weakened trunks. Some trees root very quickly – just about anything in the rose family and most maples, others are quite slow – such as most types of oaks and ginkgos. Talk to the place where you buy your tree. If they can’t answer questions like this then maybe you should find a new place to shop!