When buying new plants, most customers try to choose one that looks reasonably healthy. However, it is easy to buy a plant with healthy-looking foliage, only to discover that it is extremely root-bound when it comes out of the pot. Plants become root-bound when they have been grown in a pot that is too small for too long. They will have many woody roots circling the bottom and even the sides of the container.
If the problem is not too severe, the roots can be gently pulled apart before planting, spreading them around the planting hole when placing the plant in. However, if the plant is very root-bound, it may be impossible to pull the many circling roots apart. If the plant is placed in the hole with too many circling roots, it will have a very difficult time growing any roots out into the surrounding soil, severely limiting its water uptake. I planted a cranberry bush (Viburnum trilobum) a couple of years ago that was very root-bound, but, being in a hurry to get it into the ground, I neglected to adequately separate the roots. Although we watered it quite often, it constantly looked drought stressed and slightly wilted. The next spring, we dug it up and sure enough, it had only grown one tiny root outside of the original, intact circle the shape of the nursery pot. If we had left it long enough, it may have grown more roots and survived, but I doubt it ever would have been very healthy.
The best way to remedy this situation is to rearrange the plant's roots before putting it into the ground. To do this, fill a large bucket with water, then submerge the plant's roots into the water. Swish it around a bit and massage the roots; the idea is to wash off most of the soil so that you can see the structure of the roots. Once the roots are free of soil, they can be examined and, hopefully, untangled. This sounds pretty straightforward, but let me assure you that if you have a large plant, it can be a job for two people! Although the plant will almost certainly recover from a few broken or pruned roots, it is best to be as gentle as possible. Be sure the planting hole is ready before you strip the soil from the plant's roots, but if it is not ready immediately, the plant can wait a short time in the bucket of water (not in the blazing sun, however). When planting, make a small mound in the middle of the planting hole and spread the plant's roots around the mound, pointing down into the soil. Fill the hole with soil, being especially careful to avoid leaving air pockets around roots that could dry them out. Pat the soil down firmly and water the plant thoroughly.
Ensuring that a plant has healthy roots gives it the best possible start in your garden. If we had planted our poor cranberry bush this way the first time, it would have grown much better from the start. After we finally dug it up, washed and spread out its roots, and replanted it, it has been much healthier and happier.
Pollinators for Hardy Plums
Many people are surprised to learn that good quality plums can easily be grown on the prairies. In fact, many good varieties are available that are hardy to zone 2, and some varieties, such as 'Pembina', are readily available even at big box stores. Although some people have poor yield on their plum trees, the problem is more likely a lack of adequate pollination rather than susceptibility to cold.
In an article in the Spring 2010 edition of the magazine Gardener for the Prairies, Rick Sawatzky outlines what kind of pollinators different plums need. In short, the main problem for many gardeners is that hybrid plums cannot be pollinated by other hybrids; they must be pollinated by wild plums, which are difficult to find. A city dweller's single apple tree will probably be well pollinated, as there is likely a compatible apple or crabapple tree nearby, but it is not as likely that their neighbour will have a plum tree suitable for pollination, and plums also need to be nearer than apples or pears for adequate pollination.
So what kind of pollinator do you need? There are three main types of plums: true wild varieties, salicina hybrid plums, and salicina plum cultivars (also sometimes called Asian plums). Wild plums can be difficult to find commercially, but you can look for the species names Prunus nigra, Canada plum, or Prunus americana, American plum. 'Dandy' and 'Bounty' are two cultivars sometimes sold as wild plums but which, according to researchers at the University of Saskatchewan, are not good pollinators and are probably actually hybrid varieties. Wild plums must be pollinated by other wild plums, but they will also pollinate all other varieties of plum, including hybrids, cultivars and even hybrid cherry plums.
Salicina plum cultivars (or Asian plums) are usually very hardy, with good tasting fruit that has a short shelf life. Some examples are the 'Ptitsin' series, 'Brookgold', 'Green Elf', 'Fofonoff' (also called 'Homesteader') and 'Ivanovka'. These plums will pollinate other plums of the same type only, and can be pollinated by either other salicina cultivars or wild plums.
The salicina hybrids were developed by crossing native wild plums with plum varieties from California that were not hardy, producing hardy trees with good quality fruit. These include 'Pembina' (sometimes called 'Prairie', 'Acme' or 'Elite'), 'Patterson Pride', 'Brookred', 'Geddes' and 'Perfection' (sometimes known as 'Superb'). These hybrids will only produce fruit if they are pollinated by a wild plum, and they do not provide pollination for any type of plum, including each other. This may explain why some growers have poor fruit production with these trees.
Hybrid cherry plums are crosses between the western sandcherry and Asian plums that grow into bushes three to six feet tall and produce smaller fruit. Any two of these varieties will pollinate each other, as well as pollinating sandcherries, and they can also be pollinated by wild plums.
Of all these varieties, 'Patterson Pride' is often considered to be a worthwhile cultivar, with sweet flesh and a thin skin, and a tree with an attractive weeping habit. But remember, it must be pollinated by a wild plum!
If you've been keeping track, you'll see that any planting of plums will require at least two trees. Two Asian plums will be sufficient, or you could choose a hybrid and a wild plum. But if you want fruit from the wild plum, you would need one hybrid and two wild plums (that's a lot of jam!). As long as you have one wild plum, however, you could plant any other type of plum or cherry plum and have adequate pollination. Some gardeners have success with grafting different varieties onto one tree, and some garden centres sell combination trees (but check to be sure the varieties are compatible). Of course, the most effective solution might be to convince your neighbour to plant a wild plum tree - good luck!
Do I Need Mycorrhizal Fungi When I Plant?
I've noticed a huge surge in promotion for a product called "Myke" in my area, which is an innoculant of mycorrhizal fungi. Recent gardening books recommend is, blogs praise it, and I know of several garden centres that increase their usual one-year warranty to five years if you buy this stuff and use it when you plant. Since I always feel sceptical of miracle products, I wanted to find out if this is a genuinely effective product or just a money-maker. And, as always, the answer is probably somewhere in between.
The first question to answer is what, exactly, are mycorrhizal fungi? Simply put, they are a type of fungus that colonizes plant roots. The fungus and the roots form a symbiotic relationship with each other that is mutually beneficial. In exchange for nutrients from the plant, the fungi help plants absorb more moisture, phosphorus, nitrogen, and micronutrients from the soil, protect them from some diseases and even block the over-absorption of some heavy metals. There are many different kinds of these fungi, with probably more than 2000 species that have relationships with up to 90% of plant life.
The evidence is pretty clear that mycorrhizal fungi are beneficial to plant growth, and studies have shown that plants grown in sterile soils show better root growth when the appropriate mycorrhizal fungi are able to colonize the plants' roots. However, most commercial products are intended to be used in the garden, which is very far from a sterile environment. In fact, there are probably all sorts of these beneficial microorganisms already present in your soil. There are some situations, however, that might reduce their presence. These include fallow or monoculture situations, in which the appropriate host plants might not be present, recent fires, over-tilling, over-fertilization (especially with phosphorus), water-logged soils, or the application of systemic fungicides. After disturbance, mycorrhizal fungi will recolonize soils, but some types may move slowly and take many years to return. Many urban soils suffer from one or more of these problems, so many homeowners might feel that adding mycorrhizae could be beneficial to them.
Because there are so many different types of these fungi, commercial products contain a blend, in the hopes that one of the types included will be appropriate for the plant to which it is applied. However, the appropriate fungi may not be present in the blend, or the fungi added could actually be out-competed by native mycorrhizal organisms already present in the soil. The soil itself could also be inhospitable to the introduced species, having the wrong temperature, pH, or moisture level. Gardeners who use these products should avoid using it throughout soil, and ensure that it directly contacts plants' roots, where it has the best chance of survival.
On the topic of whether adding products containing mycorrhizal fungi when planting, the Ohio State University Extension tells us that "the available evidence is very inconsistent". These products will probably not harm plants, but whether or not it will help them seems to be a bit of a gamble. However, you can encourage the presence of beneficial fungi by nurturing healthy soils, and especially by avoiding the heavy use of phosphorus fertilizers. The old advice to add bone meal when planting to stimulate root growth may actually be harmful, as the excess phosphorus could inhibit the colonization of mycorrhizal fungi on the plant roots, actually slowing root growth.
Hopefully future research into this area will give us better answers about the effectiveness of these products; in the meantime, consumers should take marketers' claims with the proverbial grain of salt. For more reading on this topic, check out the fact sheets available from the University of Alaska Fairbanks and Ohio State University.
The first question to answer is what, exactly, are mycorrhizal fungi? Simply put, they are a type of fungus that colonizes plant roots. The fungus and the roots form a symbiotic relationship with each other that is mutually beneficial. In exchange for nutrients from the plant, the fungi help plants absorb more moisture, phosphorus, nitrogen, and micronutrients from the soil, protect them from some diseases and even block the over-absorption of some heavy metals. There are many different kinds of these fungi, with probably more than 2000 species that have relationships with up to 90% of plant life.
The evidence is pretty clear that mycorrhizal fungi are beneficial to plant growth, and studies have shown that plants grown in sterile soils show better root growth when the appropriate mycorrhizal fungi are able to colonize the plants' roots. However, most commercial products are intended to be used in the garden, which is very far from a sterile environment. In fact, there are probably all sorts of these beneficial microorganisms already present in your soil. There are some situations, however, that might reduce their presence. These include fallow or monoculture situations, in which the appropriate host plants might not be present, recent fires, over-tilling, over-fertilization (especially with phosphorus), water-logged soils, or the application of systemic fungicides. After disturbance, mycorrhizal fungi will recolonize soils, but some types may move slowly and take many years to return. Many urban soils suffer from one or more of these problems, so many homeowners might feel that adding mycorrhizae could be beneficial to them.
Because there are so many different types of these fungi, commercial products contain a blend, in the hopes that one of the types included will be appropriate for the plant to which it is applied. However, the appropriate fungi may not be present in the blend, or the fungi added could actually be out-competed by native mycorrhizal organisms already present in the soil. The soil itself could also be inhospitable to the introduced species, having the wrong temperature, pH, or moisture level. Gardeners who use these products should avoid using it throughout soil, and ensure that it directly contacts plants' roots, where it has the best chance of survival.
On the topic of whether adding products containing mycorrhizal fungi when planting, the Ohio State University Extension tells us that "the available evidence is very inconsistent". These products will probably not harm plants, but whether or not it will help them seems to be a bit of a gamble. However, you can encourage the presence of beneficial fungi by nurturing healthy soils, and especially by avoiding the heavy use of phosphorus fertilizers. The old advice to add bone meal when planting to stimulate root growth may actually be harmful, as the excess phosphorus could inhibit the colonization of mycorrhizal fungi on the plant roots, actually slowing root growth.
Hopefully future research into this area will give us better answers about the effectiveness of these products; in the meantime, consumers should take marketers' claims with the proverbial grain of salt. For more reading on this topic, check out the fact sheets available from the University of Alaska Fairbanks and Ohio State University.
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planting,
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