I have this area that im working on. Got rid of all the existing soil and will have it replaced with better quality soil. Both clay btw but the other is rock free. The area is 20ft long and 10ft wide. I plan on planting 2 crepe myrtles spaced 10 feet apart from the middle and a few juniper shrubs around the sides and the front. Since I'd be left with a lot of barren space, im thinking about installing pavers. Would that be a good idea? Will it help keep the roots cool in our dry climate or make it worse by restricting water supply to them? I'll be doing this project all by myself so I've got a few questions that need adressing. Should i install the pavers first and then plant my trees and shrubs and How much space should i leave in between for my plants?
It depends on your zone and climate. Where you have sustained periods of hot weather pavers and flag stone heat up, particularly so if they are dark in colour. The pavers radiate that heat and make that area hotter. Grass, shrubs and trees make it cooler by letting water vapour out of their leaves and stems.
You can try this yourself any hot afternoon of a summer day. Step on some grass with bare feet and step on a paving stone. You'll know which is which by temperature alone.
Most interlock companies claim that they allow water to penetrate through the joins but if you want a low maintenance solution you will use polymeric sand which slows water draining through the bricks and increases run off.
There is a product that will do what you want and can be planted with grass or tough groundcovers like creeping thyme or sedum. In my area it is called Turfstone but is sold under other names.
When installed with a proper base of 6 to 10" of crushed gravel and a layer of stone dust the plants will absorb some water, some will drain through and if properly graded large amounts of water will drain towards the planting bed. This could be a DIY project if you are handy but research what is required in your area for interlock.
I have seen this in use under heavy foot traffic with light vehicle traffic and grass stands up well with a little shade. Full sun would require tougher ground covers
I opt for a space of at least 3.5 feet from any planting, and geotextile filter fabric of the non woven variety laid above 3 inches of coarse gravel/crushed gravel(i prefer 3/8"chip), and underneath 6 inches of the same, where you can then place larger [spaced] pavers of choice in an arrangement of choice, as heat will radiate out and away due to air cushion of gravel surround. The pavers will easily maintain their level due to size and gravel bed, and water can percolate thru without worry.. the juniper will appreciate the cushion with which to root and shed..most plants need a little of their own leaf litter to decompose in the soil for their systems to be strong. .juniper gets twisty and can push up earth quite well over time. Gravel is easily spread, filled and loose pavers can be rearranged in that circumstance. Edging is helpful to keep gravel in place. Mulch is a good addition to cool the soil as it holds moisture in. Alternatively, my girlfriend lays paper bags under the top layer of soil and in a year its all nutrient rich and cool for many inches below.