I've searched the web and various posts in the rose forum to determine if I should use a top dressing in my containers. There appear to be all sorts of recommendations, including mint compost, hazelnut shells, wood chips, tree bark (but not redwood) and compost (the composition 0f which is not clear). My questions are as follows:
1. Do I need any top dressing in my containers;
2.If the answer is "yes" is there a preferred material.

Thanks

I do not know about roses but I definitely topdress my large house plants every couple of years instead of repotting them. I just put compost or store-bought potting soil.

Dennis, why not redwood, like shredded redwood as a mulch?

I read on another post on this forum that the tannin in redwood products was toxic to roses???

You can top dress but it is not mandatory. Some years I do and others I've skipped it. BUT, anything you add should be organic and good for the soil. Top dressing does help with water retention and will feed the soil. Good soil makes for good roses. Compost and well composted manure are good organic choices. Wood chips or bark are probably not the best for the soil but will help retain moisture.

Dennis--I would like to hear more about this, because two of my roses haven't done as well since I started using shredded Redwood mulch. In fact, my Double Delight hardly bloomed at all for the first time last year. I thought it might be because there is a tree nearby that keeps growing taller and taller, and maybe the roots are encroaching. Almost everytime I checked under the mulch, the soil was moist, though.. Recently read about someone else here who uses Redwood shredded mulch, like it's an ok mulch.

Rosemary-I found the reference to using redwood bark in a thread on the roses forum. It was a few years ago. I couldn't find the thread again. However, subsequently, I reviewed a bunch of posts on the Houzz forum, some of which indicate that using redwood is ok. It's confusing. Just to be on the safe side I'm going to use other materials as top dressing.

I searched for "tannin" in this forum and I think this must be the post you saw, Dennis.

https://garden.org/thread/view...

Unfortunately, it doesn't tell us much about the pros and cons of redwood mulch. It was simply a question Mike asked me about something another friend, Don, once said about redwood mulch. I didn't remember the discussion. If Don did say something about it, he would have said it on the Dave's Garden site, and I never go there anymore. Don died last year, so we can't ask him about it either.

I personally never use wood mulch anywhere but the pathways. I've found that it attracts too many earwigs and sowbugs, so I never use it near plants.

Dennis, I use liberal amounts of just (only) horse manure as a grow-bag top dressing. Since most of my newcomers spend at least two seasons in grow bags, I need to replace the organic part that was mixed in as part of my initial substrate at least once, each new growing season. A liberal amount is given by the pot/bag itself. I simply refill it until it reaches to an inch below the brim, to allow for watering. In some bags the seaonal drop is lower than others, although they are all of the same size, and were planted the same time, which just shows that nutrient uptake is not uniform. Thanks to this procedure I ensure that my juvenile roses have developed a good root mass before being placed out in their final position in the yard.
Arturo

Gertrude Jekyll was a great advocate of fresh horse manure for introducing the necessary micro-organisms to improve the soil. I use it liberally on the roses growing in the ground.

porkpal ,I see no negative effect in using fresh horse manure in any of my garden additions. The only problem that in midsummer ( now) fresh manure dries up so quickly that it takes ages later to decompose if just left on the top. Sadly, I never managed to keep horses myself, so I rely entirely on my neighbor who rents out horse rides. She keeps about 8 at least . These generate enough horse manure to amply satisfy our farm plus garden needs...(I've got to go across to bag up more for later use. )
Arturo

Dennis, I have been growing roses in pots for decades. I am with Seil. Sometimes I will top dress them and some years I won't. Don't get me wrong. I still use organic fertilizer and amendments on them. If I have "dressed" them it has been with coco shells. If you have pets, I would not recommend this topping, but I have loved it (when I can find it). It is lightweight, smells like chocolate (who doesn't love that!), breaks down and improves the potting soil in the pots.

MBN, it sounds delicious, lol!

I use both red tan bark mulch and horse manure compost for top dressing, one for finer weed control and the other one is to keep it nice looking.

Doesnt need it but it is beneficial to do even if only to reduce water use. I like to keep pots filled to the top, more water holding capacity and better insulation from heat. Heat can be a problem here (45c / 113f). Use to use compost and bark, now use a product here in Au called whoflungdung.

I read that it isnt good to put mulch [am assuming a bark mulch] directly on top of a potted rose but rather put organic material, like horse compost, down first. Something about the mulch depleting the nitrogen out of the plant [this may not be exactly correct, just what I recall]. Since I raise horses and have plenty of rotted compost, I always put a bit on top before I add the mulch. I also use a fine ground "landscapers mulch" on top of potted plants. This will disintegrate into the soil, makes the pot look neater and absorbs water into the pot instead of splashing out.

Bark using nitrogen when decomposing probably isnt really an issue if people are feeding. Feeding roses is pretty standard so unlikely to be a problem, especially with how common fish emulsion/seaweed is recommended for pots due nutrients escaping from watering.

What I've done is grown chickweed in my pots. They provide cooling to the roots in the pot and they fixate nitrogen from the air! But...make sure to cut them back before they flower.