Sunday 23 April 2017

A Guide to Planting Shrubs

A Guide to Planting Shrubs, by Ian A. Reid

I have watched several videos on the subject of “Planting Shrubs.” All the videos, I watched miss two essential steps. The missed steps are the first two listed below, as follows:

1. Determining height of the root crown; the root crown is the point of the shrub between the top of the roots and the start of the stem.

It’s very important that this point is one inch above ground level. How do we determine the height of the crown? After the hole for the shrub has been dug, lay a pole from one side of the hole to the other side intersecting the point where the crown will be positioned. Adjust the heights of the crown (where the roots start) one inch above the ground level by putting or taking away soil at the bottom of the hole. To make sure the soil is compacted, tamp the soil down by your feet or by some other means. This removes air pockets and prevents the shrub from settling over time. If this is not done, over time the crown could sink below ground level. (Hint: a good way way to tamp the soil around the roots is to place the plant, fill the hole at least partially full of water and then add the soil.  As the water is absorbed and flows away into the ground, it pulls the wet soil into the holes around the roots, getting rid of air pockets.  Also, you aren't pounding around on top of the roots.)

Before placing the root ball in the hole, scar the root ball say every six places around the ball by some instrument. The scar should create gullies about one inch deep. We have pruning saws in the southern shed that will do an excellent job.

If the sides of the soil are compacted, break up this soil with a shovel or pick before planting

2. Before digging the hole for the shrub, place a tarp on the ground near the hole to prevent the soil from the hole escaping.

Once the soil is on the tarp, remove all weeds and big rocks. Small rocks (stones) can remain. Mix removed soil from hole with compost from the compost pile near the winter storage area .The back fill should contain up to 10% compost well mixed with the soil from the hole. Before backfilling it’s OK, but not necessary, to add a little Bone meal, No other fertilizer is to be used as it may damage (burn) the delicate roots. The roots just before planting could be soaked in water for say 30 minutes.

To check that the shrub is vertical, Use a plumb bob to line up the plumb line with the stem of the shrub. Do this again at 90 degrees to make sure the shrub is vertical. The plumb bob could be hand made by attaching a weight at the end of a piece of string. The weight could be a small stone. Stand back 10 feet or so to check that the shrub is plumb.

3. Diameter of hole. As a general rule, the diameter of the hole, for ease of work, could be 2 to 3 times the diameter of pot. E.g. If the pot is 12 inches in diameter, the hole could be 24 to 36 inches in diameter.

4. Mulching: Mulching suppresses weeds from growing and the water in the soil from evaporating. The mulch should be no more than 2 to 3 inches thick. Never mulch near the shrub’s crown; leave this space clean. The roots have to breathe. Mulch that is too thick, suffocates the roots. Mulch covering the root flare restricts oxygen from the root system, possibility causing the shrub to rot and die.

5. Planting shrubs in a straight line. We have string and a measuring tape in the northern shed ready for use.

6. Spacing: The space between the shrubs should be such that when mature there is a little space between the shrubs.

As a rule of thumb, 15 feet (5m) should be OK for the taller shrubs. A lesser distance for smaller shrubs should be used. The shrubs spread at maturity can be found in Wikipedia.

7. Watering. Watering especially during the first year is very important. The potting mix probably dries out faster than the soil in the hole because the potting mix is not real soil but a mixture of other stuff.

After back filling the hole, the soil should be lightly tamped (not compacted) to get rid of air pockets and then thoroughly watered.

This watering should be repeated every two weeks or though out the growing season.

 I feel somewhat responsible for the NAGA shrubs because first, I planted, at no cost to NAGA, the 20 or more shrubs in about 2000 that were removed to facilitate the upgrade to the Hydro Facility in the South East corner of NAGA, and second, I negotiated with the Chief Engineer in charge of the Hydro’s upgrade to get the $600 to replace the shrubs removed.  If I hadn’t contacted the Company doing the upgrade, we would have not have received any money from the Company. The Company thought that the shrubs belonged to the City.

If the above suggestions are followed, these shrubs should flourish for many years.

Closing Thoughts

I have no idea how many shrubs $600 will buy. This money does not all have to be spent this year. If more money is needed to complete a Master Plan, perhaps it could be provided by NAGA.

I’m suggesting that a committee of interested gardeners be formed to prepare a Master Plan to include not only shrubs but also items like flowering bee beds in bright sun and in the shade and also the placement of Park benches.

As these shrubs grow it will be nice to sit in the shade watching the bees and birds going about their business. Many of our plants depend on bees (honey and bumble). Last summer because of the scarcity of bees, I had to hand pollinate a few plants. In addition my Mason bee house was unoccupied.

When choosing the specific location for the shrubs, remember that the grass will be cut around the shrubs. Please leave room for the big and small mowers to maneuver.

Take care,
Ian A. Reid, NAGA gardener

[Conversion factor: one inch = 2.54 cm ]