Applying mulch to your rose bed is one of the best ways to increase soil fertility, improve drainage, and promote healthy growth with plentiful flowers, but what mulch is the best for roses?
The best mulch for your rose bed depends on the soil in your garden. For Roses in sandy soils, leaf mold is best, for nutrient poor soils, horse manure should be used, in clay soils compost composed of garden waste is the best mulch, and wood chip is the best mulch for suppressing weeds.
Let’s look further at what mulch is best to use in your rose garden for the healthiest, disease-resistant roses that produce spectacular blooms…
Best Mulch for Roses in Sandy, Quick Draining Soil
When it comes to growing roses, there are two problems with sandy soil:
- Sandy soil tends to drain too quickly for the roots to draw up moisture.
- Sandy soil has a low nutrient density. (Roses are heavy feeders).
However, with a regular regime of mulch application, you can still grow healthy, strong roses with plentiful blooms. Whilst roses do like well-draining soil, sandy soils tend to drain too quickly for the roots to draw up any moisture.
The best mulch for sandy soils is leaf mold. Leaf mold has an exceptional capacity to absorb and hold onto water, yet leaf mold still has a light structure that allows excess water to drain away which is the perfect balance for rose roots.
The best thing about leaf mold is that there is a huge bounty every fall. The easiest and most effective way to collect it is with a lawn mower. The lawn mower does the job of collecting and shredding for you, saving you a good amount of labor!
The resulting shredded leaves have a greater surface area than whole leaves and as a result, they are broken down by the ecology of the soil at a much faster rate which is beneficial for the fertility of the soil.
Every autumn I raise the cutting deck of my mower and go around all the paths in the garden, and over the lawn collecting all the leaves far more efficiently than collecting by raking them into a pile.
I place all the leaves along with some grass cuttings into a heap or compost bin to get the decomposition process started and leave them there over winter.
By the time the spring comes back round the leaves have decomposed enough to the point they resemble immature compost which is perfect.
Partially decomposed leaf mold feeds and stimulates the soil’s ecosystem retains water and will not blow away. The worms will start work and pull the material into the soil surrounding your rose which will change the profile of your sandy soil to a much more fertile and favorable condition in terms of moisture balance.
The leaf mould allows the roots of the rose to draw upon the stored moisture when it needs to and the soil dries out less quickly which means the rose will now be far more resistant to drought in hot, dry weather.
On sandy soils, I like to apply leaf mold compost as mulch around the area of the rose at a depth of two inches twice a year. Always leave a few inches of bare soil between the rose canes and the newly applied leaf mold as the wood of the rose that is above ground is less tolerant to persistent exposure to moisture.
Best Mulch for Roses in Nutrient Poor Soil
In gardens of poor fertility, the best mulch to use for your roses is primarily horse manure.
Horse manure is excellent for enriching poor soil for several reasons.
Breaks down to hummus, biologically active material microbes and bacteria, fuel the soil’s ecosystem
- The manure is a biologically active material that is packed full of energy, fertility, beneficial microbes, and bacteria, all of which fuel your soil’s ecosystem and work to break down to make the nutrients in your soil more easily taken in by the roots. This is in complete contrast to compost that you buy at the store which is biologically inactive and as a result far less fertile.
- Earthworms in particular love horse manure. The more worms in the soil the healthier your garden, and roses will be. Earthworms further break down the manure and produce worm castings which is a digested, concentration of nutrients that your roses will love. The worms also aerate the soil and create channels that draw oxygen into the earth and keep the beneficial microbes active as well as creating space for the roots of your roses to grow into for better stability and access to water and nutrients.
- Horse manure creates a soil structure and retains water in a way that roses love. Horse manure can hold onto water much longer the nutrient poor soils typically do. This allows the roots of the rose to draw water from the soil when they need to and avoid the effects of drought.
If you have acquired fresh manure for your rose bed then I’m afraid you will have to play the long game.
Horse manure needs to rot down for about one season before you can use it in your garden because fresh manure applied to your garden can burn the roots of your plants during its decomposition process.
You can tell when the manure is ready to apply because the unpleasant aroma will have gone completely and the texture will be far more loose and crumbly.
To avoid unpleasant smells from fresh manure, add it to your regular compost heap and add plenty of brown material (straw, paper, brown leaves, cardboard). The brown material will prevent the manure from smelling and increase the rate of its decomposition.
I personally add the manure to my compost pile, cover it over with cardboard (to prevent weeds growing), and by the next season the manure enriched compost is ready to be applied to the roses, with fantastic results.
Chemical fertilizer is like a multivitamin whereas enriched mulch added to your rose bed is like a healthy diet as it adds long term fertility to the soil. A healthy diet is always better long term and I have seen some of the best rose blooms from roses that have had horse manure/compost mixed mulch regularly applied.
Best of all horse manure is usually free as it is an abundant waste product. Find someone with a horse or ask a local farmer and they will be happy for you to take it off their hands. You will be doing them a favor!
Some stables even have manure that has been piled up for years, so you can use it on your garden straight away without having to wait for it to decompose.
Best mulch for Roses in Heavy Soil such as Clay
Clay soil has an abundance of minerals and bio metals such as calcium, iron, magnesium, and potassium- all of which are great for growing healthy roses. This is why loam soil (which contains 20% clay) is considered the best soil to have in your garden.
However, if you have a high proportion of clay in your garden then this can be problematic. The problems with heavy clay soil are as follows:
- Clay is less porous than other soils so rain does not drain away quickly which can lead to stagnant water causing problems such as root rot for your roses.
- Clay and other heavy soils are susceptible to compaction when they are under pressure, such as when you walk on them to do the weeding or prune your rose. Compacted heavy soils make it difficult for the roots to grow and into the soil to find water and nutrients.
The antidote to this is adding plenty of organic material in the form of mulch. The best mulch is a mixture of leaf mold, grass clippings, and compost made from kitchen scraps and garden waste.
By adding all this organic matter to the surface of the soil you can over time change the structure of the soil into a light more crumbly texture. The improved soil texture will help excess water drain away from the roots which will be of great benefit for your roses.
The organic matter will also encourage more worm activity. The worms will work to pull down all that mulch into the soil and create more channels in the soil to let in air and allow water to drain. The channels also create space for the roots of your rose to grow so that they can make the most of the abundant beneficial minerals in the clay.
The addition of mulch on the surface will suppress weed growth and it makes it far easier for you to dig the weeds out when they do appear as it is so much easier to dig through amended soil rather than clay.
In some gardens where the drainage is particularly poor, I will add some builder’s sharp sand or perlite. Both of these materials will increase the porosity of the soil and allow more air and water into the soil without altering the pH of the soil.
Ideally, you will need to add this amendment before you plant your rose by digging a far larger hole than the size of the root ball and filling in the additional space with sand and organic compost.
However, it is still effective to add sand or perlite as part of the mulch as it will work its way down into the soil naturally through rainfall and as you water your rose every week. The ideal mixture is to use 2 thirds organic matter and 1 third sand when adding mulch to roses in clay soils to improve drainage.
A combination of leaf, grass, compost, and well-rotted manure, will give structure and increase the porosity, thus the infiltration rate, and enrich the soil, bacteria, fungus, microorganisms
Best Mulch for Suppressing Weeds in Rose Beds
Why spend time weeding when you can spend that time admiring your roses and indulging in their intoxicating scent?
Adding mulch to gardening is a very effective way to limit the growth of weeds to the point where it is only an occasional job rather than a common chore.
In my experience, the best mulch for limiting weeds is straw, pine needles, and wood chips (or wood bark). Out of these three, I would favor the wood chip as it is more aesthetically pleasing and gives a ‘finished’ professional look to the roses bed but they are all effective options.
These forms of mulch are effective as they are able to exclude light and space for perennial weeds to grow.
Stubborn weeds such as nettles often have established roots in your soil but when covered in a 2-inch or more layer of wood bark they struggle to fight their way through to reach the light and may die from exhaustion.
Materials like pine needles and wood bark as also less inclined to let annual weeds such as dandelions set seed, particularly compared with open soil.
I once maintained a rose bed for a client who lived next to an open meadow that was host to many varieties of weeds which released seeds with every gust of wind into their garden and fighting the weeds was a constant battle.
When the seeds of weeds land on nice fertile mulch with an open texture such as horse manure or compost then nearly every single seed will germinate and grow into a weed.
Once I applied wood bark around the roses the number of weeds establishing were few and far between. The seeds simply cannot germinate and establish roots and the more coarse wood bark.
The bottom layer of wood bark will eventually break down and add nutrients to the underlying soil too.
Wood bark can act as an effective weed suppressant for 2 or 3 years before you have to add another layer on top. And when weeds occasionally appear, they are easily hoed out as the layer of wood bark makes for a much easier texture to hoe into without much resistance.
3 years of not having to weed every week sounds like a pretty sweet deal to me!
Wood bark also does a good job of keeping the underlying soil (and thus the rose’s roots) nice and cool in the summer and insulated in the winter which is perfect. Wood bark also stops the soil from dying out too quickly on the baking hot summer days.