One of the foundations of the environmental movement has been to “think globally and act locally”. Growing and planting native shrubs is a wonderful example of acting locally to improve the environment. We do not have to wait for others before taking action. Growing native shrubs can be as simple or as complicated as you want to make it. The techniques recommended below are based on:
If you are sold on using native shrubs, the next step is how to get them. There are four possible routes – buying from a nursery, transplanting from the wild, growing from cuttings and growing from seed. Local supplies of native shrubs are seldom available. Even if they are, few groups or individuals can afford to buy stock in the numbers required for most restoration projects.
The last three options make the best use of available resources and are the keys to any large-scale projects such as stream rehabilitation, windbreak plantings or forest restoration. You can select seed, cutting material or transplants from good parent stock and know that you are maintaining or even improving the quality of the species.
Here are some general tips on collecting material – whether seeds, seedlings or cuttings. Always ask permission of the landowner before collecting. While this might seem unnecessary, it is in your best interest. At Macphail Woods, we have been developing good relationships with landowners who are happy that we can make use of plants on their property. They often have a wealth of information on the plants and can give you some history on how the area developed or the best places to collect. We have always found it worthwhile talking to landowners and they have appreciated our efforts. If a landowner finds you on private property taking cuttings without permission, it will be a bad start to what could otherwise be a good relationship.
Try to go easy on the environment and avoid degrading one area to improve another. You should never collect more than 10% of the total seed crop in an area. If others are using the same source, lower this considerably. Cuttings should be done using proper pruning techniques, leaving the parent plant in good condition and able to produce some seed next year. Finally, always collect from healthy, vigorous plants. Poor parent stock often means poor offspring, so avoid collecting from diseased or unhealthy looking plants.
Many shrubs can be easily grown by taking cuttings in the summer, fall or winter. The pages on individual species contain specific recommendations. Use the following as guidelines for all cuttings:
Use only the current year’s growth, preferably taking the cutting mid-June to mid-August. Discard the soft, fleshy tip of the branch. The cutting should be about 6 inches (15 cm) long, with the top cut made at a low angle about 1/4 inch (6 mm) above a bud and the bottom cut straight across about 1/4 inch (6 mm) below a bud, with one or more buds in between. This is the ideal that is not often reached. Try shorter or longer cuttings if necessary. The angle of cuts is a simple way of making sure that you know which is the base of the cutting. This way, you will never plant a cutting upside down (a common mistake when using cuttings without leaves). Cut the top leaves in half unless they are quite small and strip away any lower leaves.
As soon after collecting as possible, cuttings should be placed in a bed located in a semi-shaded area. The bed can be as large as you need and have time to look after. Let’s use a 4 foot x 8 foot (1.2 m x 2.4 m) bed as an example. The easiest method is to scrape the weeds off an area with a shovel or mattock and place 3-4 layers of newspaper on the ground, extending beyond the boundaries of the bed. Construct your frame out of 1 inch x 8 inch (2.5 cm x 20 cm) or 2 inch x 10 inch (5 cm x 25 cm) material and set in place. Place a 6 inch (15 cm) layer of clean, inland builder’s sand in the bed and water thoroughly. Mulch outside the bed’s base with wood chips or bark to keep weeds from infiltrating. Sprinkle a small amount of #2 rooting hormone (we use Stim-Root, available from most nurseries and stores with gardening sections), on the flat top of an ice cream container. Dip each cutting in the hormone, covering the base, just before you plant it. Rooting hormone stimulates better root development. Once it has come in contact with plant material, do not return the hormone to its original container. It can contaminate the remaining product and should be discarded at the end of each cutting session.
Cuttings should be planted so that about 1 inch (2.5 cm) of the tip is exposed. Use a screwdriver, stick or whatever you have to make a hole, place cutting to desired depth and firm sand around cutting. Place cuttings 2-3 inches (5-7.5 cm) apart, depending on species and size of the leaves. A bed this size can hold between 500-1150 cuttings. Cover the bed with white plastic, old windows or plywood – anything to keep the moisture levels high. Check weekly to see if the sand is still moist, and water if necessary. After about three weeks, start giving a little tug on a few cuttings of each species. When you feel resistance, you have succeeded in getting root growth. Dig up a few and see what they look like. You can plant them out right away in a shady, protected location, or transplant them to the nursery and wait a year or two until you have larger plants.
These cuttings can be made as soon as the plants become dormant in the fall, after the leaves have dropped, and anytime before the buds swell in the spring. Again, use the current year’s growth, discard the softest growth at the tip and make cuttings the same as you would in summer. Remember to use a slanted cut at at the top of the cutting and a straight cut at the bottom. We tie winter cuttings in bundles of 50, marking each bundle with a plastic tag and recording species, location, date and other information that might be useful. The base of the bundle is then dipped in #3 rooting hormone and the bundle is placed in a plastic bag. Store this bag in a refrigerator or cool basement, or in sand in the cutting bed under a thick layer of mulch. In the spring, as soon as the ground is workable, you have two options. Place the cuttings in a cutting bed as described above, to be transplanted later; or plant them in a regular garden bed at 3-6 inch (7.5-15 cm) spacings. Spacing depends on when you want to use the plants – wider spacing allows you to leave the cuttings in the bed an extra year if you want to set out larger transplants. These beds need to have loose soil so that the new roots are free to develop. Mulch well and keep well-watered, since a garden bed can not maintain the cutting bed’s high humidity level.
Saving the best for last is an old trick, but growing shrubs from seeds is really the best way to do large or small numbers of most species. You can select from local, reliable parents – vigorous plants with heavy crops of seed – and grow hundreds of seedlings for transplanting at almost no cost.
There are a few things you should to be aware of when growing native shrubs from seed. Most seed has some kind of dormancy – this stops it from germinating in the fall during a warm spell and freezing to death over the winter. Dormancy can be quite complex – a hard seed coat that needs to break down over a winter, an embryo that is not fully developed, chemicals within the fruit that inhibit germination, or any combination of the above. Fortunately, you do not have to worry about dormancy, as long as you follow the recommendations on growing each species of shrub. Few shrub seeds will germinate in the spring after fall planting (one reason commercial nurseries do not grow them). If you are growing some species that will germinate in the first growing season and some that do not sprout until the second spring, separate these two groups. It makes weeding and mulching much easier and efficiently uses available nursery space.
Seed preparation also differs between species – serviceberry fruits contain multiple seeds, while wild raisin has a single seed. Some seed-coats need to be removed or crushed, while others are fine to plant just as they come off the shrub. You don’t need to worry about all the differences, just follow the recommendations for each species. Seeds should be planted as soon as possible after collecting, to prevent molds from forming on the fruit or the seed from drying out. A general rule of thumb for planting depth is twice the diameter of the seed – plant small seeds such as roses about 1/8 inch (3 mm) deep and larger seeds like hawthorn about 1/4 inch (6 mm) deep. Place a 2-3 inch (5-7.5 cm) layer of mulch (eelgrass works best, but any easily-removed mulch will work) over the beds in the fall and remove most of this in the spring. If the seeds need two winters before germinating, mulch again the second winter.
A good soil is light, with lots of organic matter. It is rich, but without high levels of nitrogen that can cause too rapid and spindly growth. A mix of old manure, topsoil and any of the following works well: potato compost (available from some farm composting operations); other compost; rotting leaves or leaf mold, chopped up with a lawnmower; and peat moss. We also use various types of seaweed, fish fertilizer, mussel mud and small amounts of mussel shell in our nursery with great success.
In most cases, transplanting is not a desirable way to get much planting stock. Often you can not be sure what the parent stock was like. The act of transplanting itself usually damages the transplant and other plants growing nearby. Here are some areas where you can safely get transplants:
Most people do not want trees growing up on their forest roads. Most of the plants would get run over by machinery anyway, so this is a great place to practice guilt-free transplanting. Again, be careful of damaging roots of trees growing alongside the road – they spread for long distances at shallow depths.
If you are looking for alders to plant, many farmers will let you dig them for free from their fields that have started to grow up. Other species not wanted by farmers can be found in fields, such as willow, and hawthorn.
Often a good source of willow, alder, and red osier dogwood. These are usually hacked down by machines or workers every year, so taking some of the smaller plants does little harm.
Most shrubs are easy to transplant, especially if under 2 feet (60 cm) tall. Dig plants early in the spring before new growth has started and ideally after a rain when the soil is soaked. Most roots will be within 8 inches (20 cm) of the surface, so a wide hole is better than a deep one. A bushel basket will hold larger specimens, while small plants fit into 2 litre milk containers.
The better you treat the transplant, the more successful it will be. Here are some general tips: