Reactive Clay Soil - Gardens, Root Barriers

Hi,

For a Victorian era period home (c1900) in Northcote, Victoria, I am planning a new garden. Currently there are just a few rocks, weeds, and a vegetable garden (planted by tenants of property, 2.5m wide x 1.5m depth in area).

The area is built on reactive clay soil.

There is a small courtyard at the rear of the house (about 5m wide x 7 m long). There is garden bed on the rear fence (5m wide x 1.5 m depth). And this extends in an L-Shape to the right side of fence (4m wide x 1.5m depth). The rest of the area is paved brick. The right sided garden bed is about 2m from the rear wall/windows.

With this in mind, what sort of trees/plants/shrubs should be planted to help minimise moisture variation in the soil?

Is having a small vegetable garden OK?

Also, there are large established trees planted on neighbouring properties.

Is there a role for TREE ROOT BARRIERS around the perimeter of the garden bed or the whole courtyard?

Will this help in moisture stabilisation?

Any comments much appreciated.

GSJ

Depends on the paving, type of neighbouring trees, drainage and the foundation?
If the paving is laid on a slab, then any rain will run off into drainage. If its on a sand bed, a lot of rain will soak through. Whats the drainage like in the front and sides... paths, runoff and the like?
If you think the soil will cause you a problem (or if it is already), it might be an idea to get an expert in. Some of the older Melb houses have problems with foundations due to the drought. A architectural/building firm with a soil engineering service will be able to help.

If you don't have problems, then the existing garden bed won't be part of a problem that doesn't exist. ;)
If you are worried, you can put a arid zone garden nearest the house, building the soil up to allow rain to run off onto the paving and away from the house/into drains. (cover with pebbles and plant desert type plants that will suit the dry area - this will mainly stop you watering the area) The back garden won't be a problem, whats happening with the paving will negate its effect. Plant what you want, except trees with invasive roots.
Root barriers (plastic shallow types) don't stop invasive roots, unless you put in a deep concrete barrier the roots will go under looking for water. Better to provide water (underground drippers) near the tree to keep the roots in that area.

Not to forget.... veggie gardens are always ok, on all sorts of levels!

whoops... posted twice

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With this in mind, what sort of trees/plants/shrubs should be planted to help minimise moisture variation in the soil?

Choosing plants that have low - moderate moisture requirements, providing a drip irrigation system, making sure that there is adequate drainage and mulching the soil well will help to keep the moisture level in the soil fairly constant. Plant species that have the same level of moisture requirements together in the same bed.
Is having a small vegetable garden OK?

It's probably a good idea to keep that a bit further from the house itself.
Is there a role for TREE ROOT BARRIERS around the perimeter of the garden bed or the whole courtyard?

Root barriers can help, but the very best thing you can do is choose your shrub and tree species very carefully, doing lots of research as to whether they have invasive roots.

Will this help in moisture stabilisation?

Not anywhere like making sure that you have good drainage for storm water and garden beds, and that you mulch the soil well to protect it from drying out.

Hope this is of some help, Cheers Elphingirl

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Thanks for replies thus far.

Regarding the paving, good point, will need to check if it is on sand or concrete.