bit of a non sequitur ...

add an inch or two of compost ...

frankly .. i never feed nor compost shrubs.. they .. IMHO .. dont need to be fed.. so i wouldnt bother feeding them for that reason ...

and usually not much grows under them.. so a second reason for not doing it ..

but then again.. yours are un named.. so who knows ... i am picturing 10 foot tall lilacs ... or some such.. what are yours ....

ken

Roses

I plan to put cardboard on the soil then add 3 to 4 inches of bark mulch

Skip the cardboard.

http://puyallup.wsu.edu/~Linda%20Chalker-Scott/Horticultural%20Myths_files/Myths/Newspaper%20mulch.pdf

Unless you need to kill off lots of weeds, there's no need for the cardboard. As the mulch breaks down, that alone will improve the soil.

As said above, unless you have weeds or it's a newly disturbed bed which might bring lots of weed seeds to the surface, the newspaper layers or cardboard aren't needed. I typically use them when starting a new bed to help reduce sprouting of weeds from roots and seeds, but after that just use several inches of mulch, with more added every couple of years as the initial application breaks down, feeding the plants at a rate they can absorb the nutrients. Roses have a reputation for being heavier feeders, though mine do fine even though I don't treat mine any differently than the other shrubs, vines, and perennials that they share a bed with. I might ask on one of the roses forums (Roses, Organic rose growing, and antique roses).

Most bare-rooted roses are lined out in fields to size up at commercial production operations before being dug, warehoused and sent to retailers when the season arrives - no amending of planting holes etc. involved. If they grew fast enough for the grower on field soil before ending up with rose hobbyists and other home gardeners, why do they then need special rooting environments at that point?

Small amended beds and planting holes actually retard tree and shrub development, due to the soil modification adversely affecting how water enters and exits the amended area. This was being seen in research settings by the late 1960s.

Gary,

Soil is 90 percent of gardening.

Ask any farmer.

What is your soil like? Go outside and dig around the shrubs you are concerned about and look at the soil. What does it look like? Does it have a smell? Is it dry? What about drainage? But I will tell you, growing shrubs and trees in the worst soil in the world, that composted cow manure will definately improve your soil. Mulch also really improves the soil also.

Worms and soil buggies, that actually make soil, will smell the tasty manure and eat it, creating soil, improving the texture of the soil, improving drainage. So, you want t o attract the beneficial buggies to live around your plants and shrubs. It benefits both.

I have extremely sandy, infertile soil. Like the beach, except no water. We have hot dry summers where I live, so if you don't amend the soil with cow poo and mulch, you mine as well not bother planting anything at all.

Because of this, many people in my area plant in raised beds and pots and containers. WHich is great, but requires more watering. So, try the cow manure and mulch this year, and see if that improves your soil.

As for the weeds, well, what can I say? I have learned to ignore alot of them. LOL It takes the fun out of gardening, so I either pull it, or don't look at it.