Mulching with wood-chips doesn't work in rainy, humid & cold-zone Chicagoland. Chicago Botanical Garden, with 5,000+ roses stated that wood-chips are best for the 3 P's: play-park, picnic, and pathway. Cantigny park, with 1,200+ roses have zero mulch, just bare-dirt.

We have strong wind that splash up fungal-spores during rain, plus artillery fungus and blackspot is rampant with mulch. Artillery fungus is similar to blackspots, but it shoots up spores that form black-spots on houses' sidings, and cars parked nearby mulch.

Mulch holds moisture too well, and serves as perfect breeding ground for disease-causing fungus. I tested acidic mulch such as Cocoa mulch (high nitrogen & high potassium) and it grew disgusting orange fungus, plus my roses came down with rust in rain.

See link below on blackspots: http://edis.ifas.ufl.edu/pp268

"The infection cycle starts when spores are spread by rain or overhead irrigation from leaves or canes infected from the previous season. The conidia must be wet for several hours to infect plant tissues. Symptoms begin to appear in three to 16 days after infection. Mature conidia can be produced 10 to 18 days after infection and initiate a new cycle. Conidia are colorless and two-celled (Fig. 2b). A temperature of 64°F is optimal for black spot development, but conidia germination still occurs from 59 to 81°F. "

The problem with wood-chips for mulch is once de-composed, it's slightly alkaline, perfect pH for fungal spores to hatch, plus it has MUCH LESS BACTERIA to control the explosion of fungal population.

In contrast, topping with horse manure or soil has plenty of bacteria both for fixing nitrogen, and to suppress fungal development.

Conclusion: wood-chips robs the plants of nitrogen as it breaks-down, plus host many pathogenic fungus (blackspot and artillery fungus). Also it's at optimal pH for fungal development, with pine-bark at lower pH.

http://www.mycologia.org/content/95/4/584.full

" the growth of 15 strains of both saprotrophic and ectomycorrhizal ammonia fungi was tested on the medium initially adjusted to pH 3, 4, 5, 6 or 7 with MES, or to pH 8 or 9 buffered with Bicine. Many of the saprotrophic species grew well at pH 7 or 8; the ectomycorrhizal species showed optimum growth at pH 5 or 6. "

It is interesting to me how much rose culture can vary in different climates. What works here in the deep south would be a poor cultural practice for where Straw lives. This what makes an open forum like this so great, you don't have to rely on the wisdom of a single individual but can get collective global wisdom. Also the people who frequent this forum actually grow roses and are kind enough to share their experiences.

I can't recall ever seen a healthy garden in Florida without some kind of mulch being used. Where I live, the favorite is pine bark and I have seen many health roses gardens growing with a pine bark mulch.

Here in my hot humid climate, without some sort of mulch, the organics are burned out of the soil. Before the use of chemical fertilizers, farmers who wanted to use the same plot of land over and over had to replenish the organic materials in the soil. This was done through cover crops and mulching. Now farmers try to maintain growth of crops through the use of chemical fertilizers and irrigation without trying to maintain the organics in the soil. As the organics disappear from the soil, so does the nutrition and water holding capacity.

This is a big difference between wood mulch and bark muIch. Pine bark takes many years to breakdown and is a good mulch for gardeners who already have plenty of organics in their soil and can afford the cost. I use wood chips (and now peanut hulls) because they breakdown and provide a composted organic layer for my garden. In a new garden, when wood chips are first applied, I see a period when the nitrogen is in short supply and I have to feed nitrogen to my plants. By the second year, I don't need to water nearly as much and I don't need to fertilize. I am trying to mimic the forest floor where organic materials is constantly being renewed by falling debris. No one needs to water or fertilize the forest. In the old days in Florida, newly cleared land was called "virgin land" and was known as the very best for growing.

I am also trying to create a diverse population of micro organisms in my soil. Many fungi and bacteria compete with each other. Certain type of fungus feed on nematodes, so nematode damage is not a problem in my garden. I have been very influenced in my gardening approach by Ruth Stout and her success with heavy mulch..

I would really like to hear other's experiences with mulch.

Got my first load of peanut 2 weeks ago 20 cubic yards, It's spread and I am working on my second load, 40 cubic yards. I'm hoping that it will be enough to finish the mulching.

I mulch now instead of in the winter because I don't want to bury the seed from my self seeding annuals that are used as companion plants for my roses. See below.

Below is the way a freshly mulched bed looks. Plantings look a little sparse because August is when I cut back the plants getting ready for fall bloom which for us is like a second spring bloom.

Below is a new bed with piles ready to rake out. This is a new bed, so it doesn't have companion plants yet.

As you may have noticed, I am mulch fanatic.

Val: Agree with mulch for hot climate & sandy & loamy soil. Your pics. look good, the peanut mulch looks very nice. My clay is sticky and seals moisture better than mulch, so I don't need it. Plus Chicagoland is very windy and the wind blows mulch on my lawn, messy. I don't even put banana peels around roses .. they dry up and the wind blows them across my lawn.

Vaporvac: Great input !! Same here, I don't do wood-chips, but I get free grass-clippings from neighbors. I put those grass-clipppings on top of rock-hard clay, and the acid from decayed grass softened my hard clay.

One year I got fluffy fresh grass clippings and raked into the top 4" of my clay ... got a bumper crop of tomatoes. I prefer raking or layering grass into clay, but can't do that around rose bushes.

Thanks for starting a great thread, Valrose.

My experience with both pine bark as well as wood chip wasn't great. Pine bark was acidic and encouraged fungus. Both were attractive to termite and there is lot of termite in my area. So this winters, I didn't use any of them. I rather used dry leaves and used lot of them on multiple occasions. Actually I am using them all the time in my rose beds during this year.

Valrose very correctly pointed out that hot climate areas require mulching in summers too as high temps quickly dehydrate the top soil. This year, a layer of leaves as well as grass clippings from the lawn helped me in keeping the topsoil moist and alive. Grass clipping from lawn mowing do bring grass seeds to the bed but tilling takes care of that. Hot climate ensures quick decomposition and regular provision of minerals, specially nitrogen. The beds where I didn't mulch with leaves, the roses suffered with nitrogen deficiency.

Looking forward to more options....

best regards

Hi Vaporvac very nice writing about using compost as mulch. I agree about the soil layers, I have the same layering of soils in my yard except on top I have a layer of uncomposted material. I can get the peatnut shells composted and I am thinking about trying a load of peanut compost next year. I worry about the peanut compost decaying too fast, but it will be a denser product so maybe the added mass of material will help it last longer.

I would like to have more of my soil covered with plants, a kind of self sustaining mulch. The trick is to find groundcovers that will grow well without becoming a control problem. In the summer , I have lots of annuals in my beds and they help shade the soil.

The soil layers make measuring ph tricky, each layer having a different ph . I know that I'm supposed to mix all the layers together and take an "average" ph, but I think that the layers have the advantage of allowing plants of varying nutrient needs to grow in the same bed. I have blueberries, plums and roses growing together. Blueberries are known to need a very acidic soil, while my roses seem to prefer a just barely acidic soil and the plums will grow anywhere. I'm guessing that the layers provides different nutrients so that the acid loving blueberries are happy in the same bed as the roses.

All this soil chemistry gets very complex. I take the approach that if I take good care of my soil, the soil will provide my plants what they need to flourish.