Humboldt Rose Society

DO ROSES GROW WELL HERE ON THE COAST?

Roses on the coast, when cared for properly, will grow taller and have larger flowers than in the hotter inland areas where the hot summer sun causes the bushes to quit growing. Though we don't have the heat problem, there are some roses that need more heat than our climate can provide in order to bloom properly. That is why it is especially important here to get varieties which do well in cool, damp climates.

Another problem with rose growing here is that fungus spores are spread very readily during the wet periods. There are two basic choices. Either very carefully pick your varieties from the most disease resistant roses or have a regular spray program with a good fungicide. Information about disease resistant varieties and also good spray programs are available on this site or from the Consulting Rosarians of the Humboldt Rose Society. Visit the Ask the Experts page if you would like to send a message to one of our Consulting Rosarians.

WHICH ROSES GROW PARTICULARLY WELL IN THE SHADE?

All roses do the best when planted in full sunshine. This is especially true here on the coast. All yards have micro-climates in them, areas which are warmer or colder than the norm. It is best to find these warmer spots, preferably out of the wind.

That said, there are bound to be times when an area of partial shade could be improved by the inclusion of a rose bush. In this case, there are certain musk roses which do quite well under these conditions. Musk roses are not like a long stemmed hybrid tea rose. They usually have smaller blooms, but lots of them. They are very healthy and quite pretty in their own way.

HOW MUCH WATER DO ROSES NEED?

Roses need regular watering, whether by nature in the form of rain, or by a human in the form of applied water. In general, they need the equivalent of about one inch of rain per week. If you were watering with a bucket it would take about five gallons of water. If you water with a sprinkler, set a container for measuring in the spray pattern and see how long it takes to deliver an inch worth. In our damp climate where the foliage already gets more moisture on it than is desirable, it is best to water without getting it on the leaves.

Many of our members use drip systems. Others use the same kind of tubing to deliver the water through shrubblers, which are small sprinklers that shoot out a flat pattern that covers about a foot in area, and is low enough that it does not get the leaves wet at all. Roses in containers need more water, especially during hot or windy weather when they need water every day. Usually, watering container roses a couple of times a week is sufficient. Just watch for signs of water deprivation.

DO ALL ROSES REQUIRE PRUNING?

Pruning is important for all roses as a means to renew the plant. Most modern roses are pruned in this area during January or February when they are at their most dormant stage. Old Garden Roses are mostly "once bloomers," which have just one long period per year of heavy flowering with no repeat bloom. These roses should be pruned right after they finish blooming.

Do not fail to prune for fear of making a mistake. Roses are very forgiving and will come back from most errors in pruning better than you might think. Visit our Past Articles page for more pruning advice.

HOW CAN I GET RID OF APHIDS?

In this area we are very fortunate to have very few insect pests, therefore we rarely have to spray with insecticides. The main exception are aphids which can be totally absent from your garden one day, and then appear on the nice tender new growth on a number of roses at once. They are soft bodied insects which suck the juice out of the buds, leaves and stem. I am avoiding terms like peduncle for clarity for most people.

Unless you are overwhelmed by a vast invasion of these pests, the best remedy is to take the bud and stem gently between the thumb and forefinger and squish the aphids while not harming the plant. While this may sound gross to some at first, it is quite effective and only requires that you wander through your roses each day enjoying them. If you think that it is messy, just remember that aphids are full of your rose juice or they wouldn’t squish like that.

WHICH ROSE BLOOMS THE EARLIEST EACH YEAR?

If you include the once blooming Old Garden Roses, then the first to bloom is generally “Ispahan” which is a Damask rose. It is pink, grows vigorously to a very large sized bush, is covered with blooms for a long period of time, and is very fragrant.

If you are referring to Modern Roses only, then the first rose to bloom most years would be “Kardinal”, which is a perfectly formed, medium red, hybrid tea rose which is great for show, for arrangements, and is a very long lasting long stemmed rose in bouquets.

WHAT IS MEANT BY "SHOVEL PRUNING"?

There are thousands of roses in commerce and it is difficult to avoid getting a rose occasionally which does not live up to your expectations. Since you plant roses to bring beauty to your yard and pleasure to the senses, it doesn’t make sense to continue to grow a rose year after year which fails to bloom properly or is just plain unhealthy in this climate.

Of course, you must be sure that it is not due to lack of care on your part. Also, sometimes a better, warmer spot in your yard can effect the necessary change. Still not good? Time to shovel prune! Dig out the rose, and replace it with some new rose that seems better adapted to your plans.

WHY DO YOU USE EPSOM SALTS ON ROSES?

In spite of the name, Epsom salts has nothing to do with salt, but is magnesium sulfate. Magnesium is needed for green healthy plants as it aids in the production of chlorophyll. Most fertilizers contain little or no magnesium, therefore it is a good idea to sprinkle about ¼ to1/2 of a cup of Epsom salt around each full sized rose bush in the Spring. It is considered to be an aid in getting new basal breaks, which is another way of saying new canes growing up from the bud union. This is important for the renewal of the plant.

WHAT IS PH AND WHY IS IT IMPORTANT?

Ph is the relative acidity or alkalinity of the soil. It uses a logarithmic scale which goes from 1.0 to 14.0. 7.0 is neutral. The lower the number below 7.0, the more acidic the soil is. Most plants like soil in the range between 6.0 and 7.0, except for really acid loving plants such as blueberries, or rhododendrons. Roses usually like soil best between 6.5 and 6.8. Alkaline soil above 7.0 can be very difficult to correct.

IIn our area, soil is quite often overly acid due to leaching by our abundance of rain. Acid soil can be corrected by adding one of several types of limestone. This treatment usually takes several months to take effect, so is put on in the late fall or winter when it can be rained in. A ph test should be taken before treatment. You can either send a sample to a lab, use litmus test strips, or use one of the good ph testers on the market.

WHAT IS MULCH AND WHY IS IT GOOD FOR ROSES?

Mulch is a layer of protective covering that sits above your soil. A mulch is good under your roses for several reasons. First, it helps to hold down the growth of weeds. Second, it helps to keep the water from evaporating out of the soil. Third, it helps to keep the temperature even and insulates it from both excess heat or cold. Fourth, it makes earthworms stay at a higher level in the soil where they do more good for the soil improvement. The mulch breaks down gradually and in doing so, adds more organic material and enriches the soil. Lastly, most mulches improve the looks of the rose bed.

WHAT IS A GOOD MULCH TO USE?

This question can have a number of valid responses depending on what materials are available at a reasonable price. Agricultural products which are common in one area may be impossible to find in other areas. Many rosarians here on the Northern California coastline prefer to use shredded redwood bark which lasts a long time as it breaks down slowly. It also has a natural, pleasing appearance and stays in place quite well.

Other rose gardeners use wood chips, fir bark, rice straw, gravel or weed barrier. Whatever you can get at a reasonable price, that does the job that a mulch should do, and pleases you with it’s overall effect, would be the best one for you to get.

IS NEWSPAPER GOOD AS A WEED BARRIER?

Newspapers definitely have a use as a free, biodegradable, weed barrier which can be used in places where you have a weed problem. Because it can appear unsightly, especially when the wind catches it and blows it around, it is best to use it under your mulch. It needs to be several sheets thick to do the job. 4 or 5 sheets thick should stop all but the most noxious weeds. It may help to wet the newspaper before you lay it out. When you have occasion later to dig in that area, you will find that beneficial creatures like earthworms thrive in the conditions under the paper.

Unfortunately, the newspaper can become visible in spots when uncovered by birds scratching, or by cats looking to help fertilize your roses. It is fairly easy to cover the paper back up, and it is certainly easier than pulling lots of weeds.

WHAT TYPES OF MANURE ARE GOOD FOR GROWING ROSES?

While there may be fussy people who only use pure bat guano or some other rather exotic manure, there are a number of manures which are useful in the rose garden. Price of course is a big factor for most gardeners, especially if they have a large garden. In nurseries, steer manure and chicken manure are usually available and they are not supposed to contain weed seeds. Though if you go with the steer manure be aware that its unpleasant odor may linger in your garden for quite some time..

Horse manure is a very good option. It is readily available from various sources in the area for free, and in fact some will even load it into your pickup for you. Most has been aged for some time and can be used in the garden right away. In most cases there is a lot of alfalfa residue mixed in, and that is great for roses too. Rabbit manure can also be a good option. Feces from cats and dogs should not used in the garden, though if you have cats you know it is rather difficult to stop them from going wherever they please.

WHAT IS ALFALFA TEA?

Alfalfa tea is a kind of Spring tonic for roses to help them to get off to a good start. It is made by putting three quarts of alfalfa pellets,(the kind without molasses), into a 33 gallon garbage can with a good lid. You will need the good lid to deal with the foul aroma that will come out of that can after a few days. After the mixture has fermented for about a week, it is ready to be poured around the base of your rose bushes. While this is a good mixture on its own, you can "soup it up" by mixing a couple of cups of fish emulsion and a cup of Epsom salts into the garbage can. Stir well.

Put a gallon of the alfalfa tea around each large rose planted in the ground and a lesser amount in the potted miniature roses (until it streams out from the bottom) A really large climbing rose would probably get two gallons. This mixture causes a visible improvement over the growth on similar roses which were untreated. The smell is not really noticeable once the mixture has soaked into the soil.

WHAT IS DEADHEADING AND WHY IS IT IMPORTANT?

One of the main reasons that Modern Roses are so popular is that they have such a long period of bloom. This bloom consists of a number of flushes, the first of which is usually the best.. In order to keep the rose coming out with more flushes of bloom, you deadhead the rose. Usually this is done by cutting off a spent bloom above the first five- leaf cluster which has a node on the outside or in the direction that you wish the next cane to grow. Some varieties of rose do not have five-leaf clusters within a reasonable distance, in which case you can cut above a three-leaf cluster, again so that the resulting cane will grow the right direction.

Remember that to the rose, putting on flowers is not for looking pretty, it is for making hips and then seeds, as a means of reproduction. When you deadhead the rose, the rose has to build a new bloom for making future seeds. Continue to deadhead the spent flowers throughout the Summer and early Fall, then quit deadheading for the year and let the rose set hips. The only reason late in the year to remove the hips is to cut off spent blooms or hips which have botrytis fungus. These need to be removed to keep the spores from spreading, and also to help the appearance of the garden. For more in depth deadheading questions, please ask one of our consulting rosarians at our Ask the Experts page.

WHEN IS THE RIGHT TIME TO FERTILIZE IN THE SPRING?

In our cool coastal area, we usually prune the roses in January (and on into February if you have a lot of them or the weather slows down the pruning). At this time the soil is generally too cold for fertilizer to feed the roses. In fact, if fertilizer is applied at this time the winter rains will cause it to leach down to below where the plant roots can access it. Figure on fertilizing around the first of March. Of course if the weather is still really cold you might need to delay it. You can tell by looking at the amount of new growth on your roses. The fertilizer needs to be on soon enough to help make the new growth healthy and vigorous.

If instead of chemical fertilizers you are using organic materials such as kelp meal, fish meal, cottonseed meal, etc., you can put them on sooner, as soon as your garden is pruned, weeded, and cleaned up. These take longer to become available to the rose, but have many added benefits as a long term solution for your garden.

WHAT ARE BENEFICIAL INSECTS?

Often too much attention is paid to harmful insects in the garden, with the result that people use more insecticides that are really called for. We here on the North Coast are fortunate in having fewer insect pests that harm roses than in many areas of the country. Our most common insect pests are probably aphids, thrips and leaf hoppers. If you are not killing them with insecticides, there are a lot of friendly, helpful beneficial insects which just love to dine on your pests. These include lady bugs, dragon flies, lace wings, a large number of different ground beetles, and some good spiders.

WHY ARE WORMS IMPORTANT?

Worms are an important indicator of good soil. If you have lots of worms in your soil you should be very happy. Worms move around in the soil, keeping it loose and helping to get oxygen to the roots and helping them grow. Also, the worms eat organic matter in the soil and leave worm casting which makes the matter available to the plants for nutrition.

WHY SHOULD I AVOID PLANTING FLORTIST'S MINIATURE ROSES?

On Mother’s Day, Valentine’s Day and other special occasions, you might receive a miniature florist rose as a gift. These roses are not the same varieties as the miniatures which you would see at a rose show. In fact, these miniatures are just grown to be used for the bloom cycle they are in when bought and then are meant to be discarded. They are grown under exacting conditions in greenhouses and are not suitable for your garden. The florist industry uses these roses because they are inexpensive. If you want a good miniature check our recommended roses.

WHAT ARE MINI FLORA ROSES?

The Mini Flora rose is the latest type of rose on the market. Over recent years the hybridizers of miniature roses had to discard many wonderful roses which had blooms too large for miniatures. There was too wide of a gap between a floribunda and a miniature. Also, with space at a premium in most of our cities, the demand for smaller roses was growing. They are ideal roses for a deck or patio, and can be very good grown and kept in pots.

If you have a question that was not answered on this page or would like more specific answers to any of these topics, please visit our Ask the Experts page and send your question to one of our consulting rosarians.