The higher the number of earthworms in the compost, the more robust the plants will be. Burning is an issue with chemical fertilizers, especially the xeric ones. These sages and others that normally grow in humus-lean soil are the easiest to burn. Meadow sages love humusy soil.

My favorite compost was made with 3-4 parts ground, freshly fallen red maple leaves, one part cow/horse manure, and 1/2 part coffee grounds. The latter really attracts earthworms and helped to make a fast compost that was nearly pure worm castings. This was black gold as a potting soil amendment.

Half and half may be richer than you need, depending on your summer soil temps. The rate of humus consumption doubles every 10 degree jump in soil temps. This is a guess, derived on a rough rule of thumb from reaction rates observed during chemical syntheses I've done. I do know that humus is valuable in the hot, sandy soils of Florida and southern Louisiana and that it disappears rapidly.

Hardwood bark mulch breaks down in one year into an ideal compost for tropical salvias. The humus in the soils of their native habitats comes from similar sources (oak/pine forests). Notice I said bark, not wood (cellulose) fiber. The latter will attract termites.

Rich

Thanks very much for your expert advice and help. Ive also read that adding shredded paper to these mixes is good for drawing worms also. Coffee grounds sounds good too. Thanks

Once a bed is established I don't dig in the soil except when I'm renovating. A few inches or more of compost or aged stable manure are just added to the surface each year. The microbes and worms do all the work from there. It it not a good idea to disturb sandy soil like mine. Cultivation aerates the soil too much and the microbes quickly eat all the nutrients. I noticed this years ago by comparing the soil conditions in the veggie garden's paths which were never turned and the veggie beds themselves. After making the switch to no-till the whole garden became a kind of black sand that grows almost anything.

Clay is a different matter. The problem with digging holes in it to enrich the soil is that you are also making a swimming pool that will rot out your xeric plants in wet weather and in the winter. Better to pile up sand and compost on the surface and make raised beds. This has been effective for me in areas of the yard where water does not drain easily and allowed me to keep many a touchy plant happy.

Wardda

Thanks for your input and knowledgable insight. Basically that was my thoughts for I have clay ground and it has not been amended at all. In fact when I have dug in it I have not noticed any worms but after heavy rain I have noticed small worms had crawled up into my garage so they must be deep. My thoughts were that I could after planting hill up the ground so as to have rain run off, but then I guess I would actually have a slightly raised bed by doing that , but I do know what you are saying.

Hill up the ground first and then plant. It will probably take a couple of years to find out exactly what you can do. That is part of the process and the fun.

Wardda
Ok IM going to sound like an idiot to you for I thought knew what you saying , but maybe I dont. It almost sounds like you saying to not disturb the soil at ground level sod and all and just add soil above ground , but that way the roots certainlly cant go very deep once they meet the grass and undisturbed ground. Neeless to say Ive never planted in raised beds before, be gentle.

Before building a raised bed, you may want to remove the sod level. You should certainly check for surface feeding roots of greedy trees like dogwoods and especially red maple. I have lost large stock plants to root invasion by red maples into the pots that were placed on the ground within the drip line. This is defined as the dry area under a tree where a light shower has not reached (no wind). With a red maple, I'd go to 1.5 times the drip line.

Yes the grass must go. The rotting mass of dieing sod can outright kill your plants. I hadn't considered maple roots which are a big problem in my own side yard. As to your clay, unless your soil is incredibly compacted the roots should get through. A few years ago I did a hummingbird garden for a nature center near here and the site was in a wet area on clay. The center kindly brought in a truck load of sand and a load of sheep manure and the surface was raised by less than six inches. The results have been a very pleasant surprise and against my expectations. Black & Blue perennialized, as did Uliginosa, and Microphylla San Carlos Festival, even Pineapple Sage and one of Richard's greggii cultivars Navaho Bright Red. Last year the rather tender Indigo Spires returned. That garden was good enough to attract the interest of several other nature oriented public gardens around southern New Jersey. And that has made life just a little more fun and interesting. You are going to love your garden.

Thanks guys for your expert help. Yes Im sure I will be satisfied with the outcome, in fact im getting excited about it right now.

Steve,
I also have very heavy clay soil and I have built raised lasagna beds and it has worked like a charm in every area that I made them. I also use LOTS of coffee grounds in my compost and my worms love me and I love what they are doing for my garden.

Penny

Ive received a lot of expert help on this post and I have the compost and the coffee grounds and am ready to go. just getting back on for I had fried my hard drive , Im lucky to have a son whose a pc genius, and quickly got me going again.

Besides coffee grounds, I always add banana peels and eggshells to my compost (plus other kitchen scraps).
When planting rosebushes, if I don't have any finished compost, I plant grounds, peels & shells with the bush.
Attracts those wonderful worms. And I'm on pure clay.

Carol

Now to renew this conversation, tree roots wont be a problem here, its just clay soil and rocks. I just got through planting some tomato plants using a raised bed method. this area behind my house had not been disturbed and I dig the hole removed the sod put the dirt baack in the hole and used garden soil and composted cow manure. The compost is about 40%. This bed is several inches high and quite mounded. Last year I didnt ammend my soil for tomato plants at all and got an ok crop , but not what I thought it should.

But a question now for the salvias would the garden soil[scotts] be too rich for my salvias, when the time comes and what about the agastache plants that I have or am I being to picky.