Soil Preparation and Planting*


I’m inquiring about proper soil preparation for planting the following:
1. yew hedge
2. japans maples
3. bobo hydrangea,
4. japanese blood grass, all gold hakoni grass, sunrise hosts, peonies, clematis etc.

Our soil is layered as follows:
1. 5″- 9″ of fresh triple mix on top
2. some soil 2-3″ of regular soil in some places under the tripe mix
3. 5″ of what looks like a clay (lesliville area closer to dundas st). its a higher sand colour. it comes apart in chunks when you brea it up. then falls apart if you rub it between you hands. if i make it into a ball and left it on my table it became solid.
4. regular dirt going down below, but didn’t dig much deeper then 2ft anywhere (in some place there is bricks etc in it which we have been removing).

Do we dig 2 feet deep and mix up the clay and the under soil. The clay is a layer and you can definitely feel it as a hard surface when you put the shovel through the ground – but its not rough to get through it (its only about 5-7″) . the dirt under is pretty easy to dig.

I understand yews don’t like wet feet and also that they should be watered deeply to get the roots to go down – worried the clay layer would be a “hard stop” for them.

Also what does deep watering mean? if we use a wand type attachment on the gardena sprayer and either use the sprinkle (shower type setting) or the out of tap type setting (with a slower flow). how long do you consider watering it.

is it simpler just to use a watering can so you know how many litres to pour on the new plant and the new few weeks after, etc. We want to ensure to do it proper to encourage deep root growth so that they don’t dry out like the homedepot cedars you see around. yews are supposed to be resilient once they are settled.

how often do you water baltic ivy ground cover (planted begging of october) under a huge old maple tree with a very shallow root system (front yard of a small city lot)

appreciate you help – tried to come to the farmers market but missed you guys there.



Thank you for contacting Toronto Master Gardeners. You refer to a picture but unfortunately it did not come through.

You cover many different things with your question so I will break it down into parts.


Before beginning to plan soil preparation it is important to understand that soil is not a sum total of it parts but is rather an ecosystem. It takes many years to create a healthy soil.

Soil consists of many parts. You have the Sand, silt and clay as the different types of particles as well as organic matter and pores. The different particles in soil are different shapes and fit together differently. Between the particles are small and large pores and mixed with all this are the insects, worms, bacteria and fungi that all work together to make nutrients, water and oxygen available to the plant roots. As soon as you start digging this ecosystem is destroyed. The small pores that are essential to making water and nutrients available to the plants collapse and soil starts to become compacted. The more you dig the more collapsed the soil becomes. Turning over soil down to 2 feet would not be recommended. The most efficient way of improving your soil for all plants is to amend on top of the soil followed by mulch and allow the community of soil organisms bring the nutrients to where they need to be. If you begin digging up the clay you could end up with soil that is hard and cement like. The following two links explain soil structure and working with clay.

There are many amendments out on the market for adding to soil but before beginning to look at them it is essential to do proper soil testing. No matter which plants you plan to put in your garden it is important to know what you are starting with. It is not uncommon for gardens to have most of the nutrients they need and adding can lead to toxic levels of various nutrients. The following link has a list of soil testing facilities here in Ontario.


As you are worried that the clay below will affect water drainage it is important to water when needed. When watering it is important to first assess the dampness of the soil. Having a rigid schedule and volume does not work as the weather is always changing. The amount of water and frequency will change throughout the summer and in different areas of the garden. Sticking a finger well into the soil is a good way to see if the soil is dry under the top layer. If watering is required it is better to water slowly and deeply. This is especially true with trees and shrubs. This is where the pores in your soil are used. The large pores allow water to pass right through while the small pores which actually supply the water to the roots take more time to absorb the water. When watering shrubs and trees using a soaker hose or irrigation system for at least half an hour allows the water to absorb into the soil and not just run off the garden. Deep less frequent watering will encourage deeper root growth and more drought tolerance. It is best to water in the morning as leaves have time to dry before night fall decreasing the risk of mildew.

Another key factor to watering is to mulch the plants with wood chips. The mulch keeps the soil lose, avoids pooling and hard spots on the surface, decreases evaporation and keeps the soil moist for longer periods of time. The mulch will breakdown over time and replenish nutrients in the soil and encourage soil structure and health. ( please make sure the mulch is not up against the trunk of the shrubs and trees as that can promote breakdown of the bark.)


You have a wide variety of plants listed above. Once you have a better idea of what your soil contains you can start planning your garden. When planting it is important to take into account the light levels, exposure to weather, animal/people traffic, and the surrounding vegetation to find the best places for each of the plants. It is important to know the mature size of the plants so you can leave enough room for them to spread as they grow.

Much research has been done in the last few years and it is becoming evident that the best way to plant your new plants is to not add anything back into your hole other than the dirt that was removed from it. If you add any fertilizers to the hole you will encourage the roots to stay in the hole close to the plants. You will not have the roots reaching out for water and nutrients. The fertilizer may initially show growth but over time you will have a weaker plant. This is especially true for shrubs and trees and can lead to the tree/shrubs not being well anchored and over time not thriving. When planting your trees and shrubs it is also important to rough up the roots and remove some of the soil in the container. You want your roots to be fanning out from the trunk not still contracted in the shape of the pot. If there is any burlap or wire around the roots remove that as well. When planting it is important to not plant to deep. When you look at the trunk you will see where the main roots branch off. This spot should be at ground level not below.

This Toronto Master Gardener Gardening Guide discusses planting trees and shrubs.

Many of the plants you mention have a range of needs. For example: the grasses will want nitrogen to grow well but the flowering plants will not need the same amounts of nitrogen as that will increase green growth but not flower growth. Different hybrids and species of each of these plants will be a little different. It is important to pick the hybrids and species that most closely require the environment you have in your garden. If you can do this it will decrease maintenance and possibly frustration and lead to a more beautiful display. Labels on the plants themselves should help guide you to choosing plants that are suited for your soil and will have the correct size and shape to fit into your design.

There are many articles already in our library which discuss the many different plants you list. I have pulled some links from the library for you but there are many more.


You mention that you want ivy as a ground cover. Please be aware that it is on the invasive species list for Ontario and will need some extra care. This link will give you that information.

Good luck with your project and with careful planning you should have a wonderful garden.