The soil in one of my flowerbeds that gets the morning and early afternoon sun needs enriching. It is very dry. Seems like roses is the only thing that grows there. How do I make that soil richer in the Fall. I have planted some of my WS plants there but they don't seem to be showing much growth. Last Fall, I was given a garden phlox and a black eye susan. Those have great growth so I am hoping they will bloom this summer. The 3 rose bushes that are planted there do beautifully. With the exception of the minature rosebush that I planted, the other two rose bushes were there when we moved here so I have no idea what variety they are, except what color blooms they produce. An ice plant that my daughter bought back from the beach has managed to grow there but hey, they should grow anywhere, right? I am surprized that the roses grow there. Most of that flowerbed is under the eaves of the house, so it doesn't get a lot of rainfall. I just transplanted a monarda that somebody gave me there, so I am hoping it takes off. Somebody else sent me some liatris and they have taken off and are showing potential. Would love to get more low maintence perennials started there. Any suggestions about enriching that soil? What do I add? top soil or garden soil or soil with composted manure?
Short answer: organic matter and ground cover. Compost (and other dead stuff) feeds the critters in the soil, and mulch/plants cover the soil to insulate it and retain moisture. Are you willing to defer the glory of floral profusion in this bed for several months to a year, or do you need a less-efficient fix soon?
For an immediate start that is inexpensive, I would add thin layers of Alfalfa pellets, straw, spent coffee grounds & some form of mulch over the top. This can be layered & will not harm the plants. No matter what you do, it will take time to improve the soil, but with some of the different ideas in the links P. Pirate posted, the sooner you begin the process, the better.
I use what I described first, with the addition of a layer of horse manure : I do not dig it in, but it's covered with fine bark, so it doesn't look funky! The worms will move into this area & work the layers for you. (so accomodating of them!) Besides enriching the soil, it also helps conserve moisture in the summer heat & makes for easier weed pulling.
This layering can be repeated as needed until Fall. I am in a maritime climate which has cool summers, so things take a bit longer to break down. Folks I know in warmer/hot climates see the layers settle more rapidly.
This is just one way to deal with your situation. Perhaps others will chime in with methods that have worked well for them.
Pippi - I hope you are able to land on something that meets your expectations. Please post with your results - I like to know how people resolve these situations, especially when different from mine. It really helps to broaden my perspective!
Once roses are well-established they are hard to kill. Yours probably have deep roots and have become adapted to their environment. They are in the same family as blackberries - and you know how hard they are to get rid of once established!
I agree with the others: add lots of organic matter to the area - anything you can get your hands on. It will take time, but your soil will improve.