My rockrose is still young and in a pot but ii is starting to go brown on the leaves, which are falling off in the middle and turning brown.
Has is received to much water?
Heavy rains could cause this.
You could try treated with Neem Oil also, as it is both a fungicide and pesticide.
Here are a few links.
https://www.gardeningknowhow.com/plant-problems/pests/pesticides/neem-oil-uses.htm
https://www.gardeningknowhow.com/ornamental/shrubs/rockrose/how-to-grow-rockrose-shrubs.htm
I have a rambling rock rose which has been amazingly resilient. I wondered if I would be able to take cuttings to produce more plants?
It is possible to take cuttings and get more plants but the success rate can be frustrating. I recommend dipping the cut ends of the cuttings you try into a product called Olivia's Cloning Gel. It has worked the best for me in getting cuttings of all types to take root well.
Should you cut of the flowers as they die off during the growing season?
Sure. For the roses dead head by cutting below the leaves just below the flower and above the next set of leaves down. Right above the second set of leaves down from the flower. You should see some new growth forming at the node at this point I haven't dead headed rock roses, Cistus, if we are talking about the same plant. You can prune them back during the season if the plants are overgrown, but deadheading will encourage the plant to rebloom without removing any stems responsible for the next set of blooms.
Most rosebushes need deadheading (the removal of old spent blooms) in order to repeat bloom well. The exceptions to this rule are the Knockout roses and the Home Run line of roses, for those you just pull the old dead petals off to tidy them up and leave the rest.
For rock roses I believe you are referring to Portulacca's or Moss Roses as they are sometimes called. You do not have to remove the flowers when they are done but the overall plants look better if you do. They will continue to bloom either way just fine.
If I trim now will it bud again for next year? White Rockrose (Cistus corbariensis)
I would not recommend pruning these. It is unnecessary, and can promote infection. They will only need pruning to remove dead or decaying matter. Other than this, they are best left alone.
This article will help: https://www.gardeningknowhow.com/ornamental/shrubs/rockrose/how-to-grow-rockrose-shrubs.htm
I would like to grow Rockrose to use with other herbs for a medicinal tea. However, I live in the southern part of Pennsylvania (Somerset County) and would like to grow this as a potted plant. Would I be able to grow it as a potted plant, and do I live in the right growing zone for this plant? Also, what parts of the plant are used; could I use the petals and leaves for a tea?
Unfortunately, Somerset County is too cold for rockrose. I think it would be difficult to grow in a pot as even compact forms grow 5 ft. tall. https://www.gardeningknowhow.com/ornamental/shrubs/rockrose/how-to-grow-rockrose-shrubs.htm
I have a few Helianthemum Rock Rose plants measuring about 3" x. 2" . They are in pots and i just put them outside in the daytime bringing in unheated conservatory at night. I am wondering if i am keeping them too moist as i do tend to over water than under water. Am i doing the right thing for these plants please. Any helpful advice appreciated
No matter the plant, underwatering is far better than overwatering. This is the leading cause of infection in plants, and should be avoided. Without a photo, though, it will be hard to say.
Since these are very drought tolerant, these will want to be VERY DRY before watering again. This article will give you a better idea of the care that these require: https://www.gardeningknowhow.com/ornamental/shrubs/rockrose/how-to-grow-rockrose-shrubs.htm
Like more info on care of this shrub but have forgotten the name
Without close up details of leaves and flowers, it can be hard to pinpoint, exactly, what it could be. I'm inclined to say that it is a Cisctus, or type of Rock Rose, but without being able to see the flowers I can't say for certain.
This article will help you to compare: https://www.gardeningknowhow.com/ornamental/shrubs/rockrose/how-to-grow-rockrose-shrubs.htm