Last fall, I moved to a new home in Palm Springs and began tending the existing plants as well as converting a scruffy back yard lawn area into a vegetable garden. Some of the things I've done may be useful for many of you, especially if you have less-than-ideal soil conditions.
Bordering the sides of the my front yard are several rose bushes, about 10 in each row, growing in narrow beds covered with white gravel. They had not been tended for some time, so I began by removing all the dead canes and cutting the rest back to 12-18 inch stubs.
Next, the decorative gravel had to go. It looked nice, but provided no nutrients or organic matter. Non-organic mulches force a grower to continuously feed the roses with liquid fertilizer, which I was not about to do. My goal is always to create strong and healthy plants by encouraging big populations of beneficial microorganisms and earthworms in the root zones.
So as to not disturb the roots, I like to use an "enhanced mulch" strategy for existing plants, layering useful ingredients on the surface of the soil. For the roses, I first scraped away the rocks to expose bare soil to about a foot out from each bush. Then, I scattered a couple large handfuls of multi-ingredient dry organic fertilizer and a cupful of our MycoMinerals product (which has a broad spectrum of minor and trace minerals, plus mycorrhizal fungi spores and biostimulants - see www.mycominerals.com - around each of the bushes.
Finally, I cover-mulched the fertilizer and MycoMinerals with about four inches of bagged potting soil, keeping it away from the rose graft joints. I would have preferred good compost, but it is nearly impossible to buy at stores. Peaceful Valley has some very good composted material by mail-order - see www.buyorganic.com - but this time I opted to just buy potting soil at a local store. Note that most of the bagged material sold to "amend soil" is pretty awful stuff, but some potting soils are not too bad for mulching purposes.
After putting the above materials around the roses my work was essentially all done except for occasional watering. As the bottom layer of the mulch decomposes, earthworms and soil microbes will feed on it and transport the digested organic matter down to the rose roots, taking some of the fertilizer, minerals, and mycorrhizal spores along at the same time. This will give the roses every possible nutrient they need for maximum good health and disease resistance.
As the colonies of bacteria, fungi, worms and other beneficial organisms build in numbers, the mulch layers will begin to disappear very quickly. As soon as it gets eaten down below an inch, I'll repeat the layering process to maintain a constant source of fodder for my now-abundant soil critters so they (and the roses they support) don't starve.
This enhanced-mulch technique can be used for any shrubs or trees. If you want to gauge how well it works, try it on a few of your plants instead of chemical liquids (but don't ever apply any liquid NPK to the test plants - that unnatural drenching of fast-acting fertilizer will disrupt the soil organisms you are trying to build up).
For my vegetable garden, I removed the grass, turned in a load of compost from a local nursery supply, plus dry organic fertilizer and MycoMinerals. Then, to activate the mycorrhizal fungi spores - which only come out of dormancy when they sense a growing root nearby - I seeded Crimson Clover and let it grow a few inches high before digging it in. A neighbor had told me that there were no earthworms in the desert soil around here (he uses only synthetic NPK fertilizers), and sure enough, I didn't see a single worm in the old lawn area when I first dug it.
But guess what? When I turned under the Crimson Clover, there they were - lots of fat happy worms! I don't know where they came from, but if you provide the food they always seem to show up, and now that I have the garden soil set up with organic matter, minerals, and mycorrhizal fungi I'll never deep-dig it again, which would destroy the worm tunnels and disrupt the valuable microbial colonies. I'll simply do the enhanced-mulch between rows on the soil surface and then seed or transplant without digging any more than necessary. I also try to avoid stepping on the beds. I'll either reach in from the sides or lay down a wide board to walk on. An alternative would be to create permanent walkways between your designated no-step planting areas, making the beds just wide enough to tend from the sides - maybe 3-5 feet wide.
Again, I suggest giving this technique a try if you are still doing springtime rototilling (a horribly destructive idea, from a worm's perspective) or using synthetic NPK "plant food." I think you might be very surprised by how much better your plants perform, plus how few disease and insect problems you have with this biology-oriented method. Fully nourished plants have good built-in resistance to disease, and if a plant is not artificially forced with high-analysis fertilizer it does not invite insect attacks.
Good growing, my friends,
Don Chapman
President, BioOrganics