Watering Roses in Summer

Q. Dear Mr. Karwin: I can’t find any guidance in my various gardening books on how much water one should give roses after they have stopped blooming (most of mine have), especially between now the beginning of the rainy season. Any suggestions? Many thanks.

August 2013

A. Roses should be watered even after blooming to keep them healthy and growing. This is important during hot summer weather, when the plants could be heat-stressed. Be sure to let them dry out between watering sessions, particularly for roses in containers.

Here is independent advice (unfortunately I lost track of the source):

Summer Watering Tips

Roses like infrequent, deep watering as opposed to watering a little bit every day. They prefer a good deep soak and then like to be dried out before receiving another deep watering.

How do you know if your roses need water in the first place? The leaves may droop and lack the suppleness they normally have.  (Don’t confuse this with the drooping that often occurs when temperatures exceed 90 degrees).

How will you know if you’ve watered too much? The foliage may feel spongy and may turn yellow. If watering from overhead, do so early enough in the day so the foliage has time to dry out before nightfall.  Spraying the leaves with water will often wash away any disease causing spores before they have an opportunity to take hold. So don’t hesitate to do this on a hot, dry day. Your roses will thank you for it!

Best wishes,

Planting Soil

Q. Can you tell me where I might order good soil to put in raised beds I recently created?  I want to be sure to have good quality and no weed seeds, etc.  I put down weed block cloth and wire to try to keep out gophers. If you have any suggestions not only about where to get it but whether it should be top soil or whether I should add compost or anything else, I’d appreciate it.   I’ll need it delivered.  And, do you know a good source for pea gravel?  Where I used to live, some places had trucks with separate compartments so they could deliver soil, rock and bark at the same time.

 Thanks for any help you can offer.  I really enjoy your column, especially about good plants to grow locally that attract birds and wildlife but don’t take much water.  I’m gradually replacing the lawn with plants that can live with no or very little added water once they are established.  If you have any particularly good sources of information about such plants, I’d love to know that also.

A. To have top soil and pea gravel delivered to your garden, you should contact a landscape supply yard  directly. If you go through a landscaping service or garden center, you will likely pay more for the same service.

I assume your garden is in Monterey County. I found just one such service in Monterey County. Here it is with two others that will deliver to Monterey County.

Tri-County Landscape Supply  Location: Elkhorn (Monterey County) No personal experience.

Aptos Landscape Supply  Location: Aptos.  A few months ago, I bought rock mulch from this place, and was pleased with the service, but a friend recently complained that they delivered top soil that was much inferior to what she had selected at the business location. Weed seeds were not a problem, but the delivery resembled fill soil. A good practice would be to examine closely any supplier’s delivery before it is unloaded.

Central Home Supply  Location: Santa Cruz. I have use this service for years and always found them fairly priced and reliable.

You might call for phone bids from each supplier. It’s also helpful to walk around a yard to see what they have to offer. These places are good sources of ideas!

Delivery charges will be based on distance, as you might expect. These services have methods to keep separate different materials in the same load. Each delivery costs, so its most efficient to include all you need now (or could store) in the same delivery.

Best wishes

Q. Thanks very much Tom.  I live in the city of Monterey.  I gather that since you didn’t mention nurseries that either they don’t sell in bulk or that they are more expensive than the places you indicated?  Would you recommend that I also get some sort of compost to add to the top soil?  I don’t have a very big yard, so don’t compost myself.

A. My comment about garden centers also applies to nurseries (which grow plants to sell to garden centers). Most nurseries are wholesale operations that leave retail sales to garden centers and places like Home Depot. The retailers all sell garden soil in bags.

Depending on how much soil you need, buying bagged soil might be less expensive than a delivery from a landscape supply yard. Landscape supply yards offer material by the cubic yard. One cubic yard equals 27 cubic feet. Garden centers offer the same materials in bags that are typically 2 cubic feet. It’s worth comparing bids.

You should ask about the content of the soil that’s available. Ideally, it would be 4-5% organic material, which is typical of good natural garden soil. If the product doesn’t include about that much organic material, it would be good to ad compost to your raised beds. Again, the best price between bagged and bulk compost will depend on the amount that you need.

Plant Selection – Hyacinths

Q. I just purchased pink Hyacinth Orientalis bulbs from (Seattle) Costco, and am wondering if they will do well in my Seaside home?  I’m headed to Monterey in December.

I’m on a hill about one mile inland.  Some Smith & Hawken paperwhites I’ve planted over the years are hanging in there, but the USDA map says I’m zone 10A and the sources I’ve found say hyacinths are best zones 3 – 9, but may need chilling over zone 7.

I want them to be perennials, because I’m not always there in bulb planting season.

Should I plant them (I love the fragrance!!) or take them back as a mis-purchase from  a childhood memory?

A. The hyacinths should do fine in Monterey!

Hyacinths are spreading in my garden with no special care. I try to dig them up after the leaves wither and replant the bulbs for better distribution. They should be planted six inches deep, in a bed that receives at least six hours of sun daily.

Some cultivars might need chilling, but most do not. According to White Flower Farm, “most bulbs will root properly if the temperature does not stray too far above or below 40 degrees F during the rooting time.”

Q. Thank you for that information!

Nice to know you are available and so very quickly responsive!

Shrub Selection

Q. I love your column and appreciate that you invite questions.  I want to grow a thick but attractive shrub on the shady side of my house.  It receives very little sun there and is somewhat damp.  Do you have any suggestions?

I live between Fremont and Del Monte off of Montecito in Monterey, if that gives you an idea of the weather.

I like tea trees and they do well in my front yard, but there’s more sun there.  A friend recommended Dodonea, which I’m not thrilled with, but it would be okay.  I don’t know about Abutalon, it might need more sun.

If you could suggest something, I would be most grateful.

A. The Dodonaea is an interesting option, but it’s a tropical plant that appreciates more sun than you seem to have in this spot. Here’s a link to a description of the Purple-leafed Hop-Bush, from San Marcos Growers:

The Abutilon also prefers full sun. It’s attractive but may be more open in structure than you are looking for.

I prefer to recommend California native plants, as you might already know. A very good California native shrub is the Ceanothus (California Lilac), which would do well in your garden. I have a list of over twenty Ceanothus species that are shade tolerant. I could narrow down that list to a few options for your situation, based on the mature size that you would want for a plant in this location.

Let me know what height and width you have in mind for this plant.

Q. Wow!  You’re wonderful!  Thank you so much!  I agree that natives are the best, but I forget that.  Not quite there yet.  The ideal height would be around 7 feet tall.  It would be along a fence, so the width of the area I want to cover would be about 30 feet.

In my rush, I had forgotten to check what the Ceanothus looked like.  Of course, having grown up on the Peninsula, I am very familiar with it.  It’s flower is soapy, as I recall from having smashed them as a child.  This is a beautiful plant, full of color!  I love it!   With the dimensions that I gave you, do you think it would work, where would you recommend I buy it, and do you ever recommend gardeners?  Thank you!

A.

I reviewed the lists of such shrubs in a couple reference books, and searched through the inventories of some likely sources: San Marcos Growers, Suncrest Nursery, Las Pilitas Nursery and Yerba Buena Nursery. They all list several Ceanothus plants, but most are sun-loving, and the shade tolerant varieties tend to be low-growing. The remaining candidates might or might not be in stock at present.

So, on a recent visit to Native Revival Nursery, I found two varieties of Ceanothus thrysiflorus that might meet your needs. Both are listed as being shade-tolerant and capable of growing to 10 feet. When grown in partial shade, I would expect that they would not reach their maximum height, but would top out closer to the seven feet you have targeted.

These plants are in stock  at Native Revival Nursery (2600 Mar Vista Drive, Aptos).

They have both varieties in 5-gallon size for $24.99 each. The Snow Flurry is also available in 1-gallon size, for $9.99.

Blue Blossom grows to six feet wide, so for a 30-foot screen you would need five plants.

Snow Flurry grows to 8-12 feet wide (perhaps 8-9 feet wide in the partial shade), so you would need four plants.

You could mix the blossom colors, too!

Best wishes. I hope this helps.

Q. What a wonderful resource you are!  Thank you for these ideas and attachments.  I have written to the nursery and let them know that I’d like to buy three Blue Blossom and two Snow Flurry.  Thank you so much for your help!

Tree Identification (Pineapple Guava)

Q.  Could you please give me the name of this tree.

Ri%20thumb%20fruit Rick%20tree

You have helped me in the past.

A. Your plant is a Pineapple Guava (Feijoa sellowiana), a cousin of the Chilean plants, Luma and Ugni. Michael Kusiak, president of the local chapter of the California Rare Fruit Growers, identified it quickly when I asked. He said, “Once you train your eye to them, you will see them all over Santa Cruz County.”

Here’s a link to a short YouTube video about the Pineapple Guava.

Buddleia Pests

Q. Recently I had the gardener take out two buddleias as they were wormy and nothing seemed to help.  Now I have to replace them. The area receives sun from around 11:00 am on. One big drawback is that whatever I plant there must not be attractive to deer, if that’s at all possible.

I live on the corner of two streets and according to city ordinances my fence can be higher than 4 feet which is nothing for the deer. The gardener suggested potato bush, what do you think?

Do you have any suggestions as to what kind of flowering shrub and when to plant them?

Thank you very much.

A. Your plants probably were being eaten by the buddleia budworm (Pyramidobela angelarum). I once removed an otherwise healthy buddleia for the same reason.

Monrovia, a wholesale nursery that provides plants for many local garden centers, lists 160 deer-resistant shrubs that would grow well in a sunny location in the Monterey Bay area. We should recognize that few if any plants are deer-proof: a really hungry deer will eat just about any plant.

The blue potato bush (Lycianthes rantonnetii or Solanum rantonnetii) will grow to about 8 feet x 8 feet, and would be a suitable replacement. However, it is attractive to both aphids and thrips. This is not the same as the potato vine (Solanum jasminoides) which is also deer-resistant, but which has a different growth pattern. Another potato bush (Solanum crispum ‘Glasnevinis not considered deer resistant.

Another good choice would be the Abelia. Click here for information on ten varieties, almost all of which are deer-resistant.  I have four Abelia x ‘Edward Goucher doing well in my garden (where deer don’t visit).

If you would like to try buddleia again (with a plan to manage pests), here is information on 23 varieties, most (perhaps all) of which are deer resistant. It’s easiest to consider a variety that’s in stock at a local garden center.

There are ways to manage the buddleia budworm, but they are not easy, partly because it can have two or three generations in a single year. The method, briefly, it to cut the plant low to the ground in the winter (to eliminate over-wintering pests) and then whenever the pest shows up, spray with Bacillus thuringiensis (“BT”). A widely available product is Safer Caterpillar Killer.

I hope this helps.

Rose Leaves in Winter

Q. I have a question for you about my roses. I live in Pacific Grove, my roses have leaves on them. Should I strip them off or cut below the leaf growth? One of my family members says leave them alone.

December 2013

A. At this time of the year, it’s appropriate to strip leaves from roses to encourage dormancy. Just pull them off by hand and rake up under the rose bush to minimize any disease and over-wintering pests.

Roses for Foggy Areas

Q. Are there any hardy roses you would suggest I could plant that will survive Pacific Grove’s sandy soil and fog?

I enjoy your column.

December 2013

A. In December, it’s appropriate to strip leaves from roses to encourage dormancy. Just pull them off by hand and rake up under the rose bush to minimize any disease and over-wintering pests.

Treat the sandy soil and fog as two different issues. (They are both manageable.)

Sand in the soil helps drainage (which roses and most other plants appreciate), but there can be too much of a good thing. The sand content of your soil should be between 10% and 30%. I recommend analyzing soil texture so that you will know what you have. Here is a link to Fine Gardening magazine article, “How is Your Soil Texture?” that describes a simple procedures that you can do in a few minutes and without cost.

If this test shows an excess of sand, add compost or other organic material to improve the mix. During January or February, you could lift the rose, dig a hole about twice the size of the root ball, fill the hole with a mixture of garden soil, sand and compost, replant the rose, and water in. There is no correct mixture, but you might try for something like 70% soil, 20% sand and 10% organic material.

When lifting the rose, first use a shovel to cut the roots to about six inches around the plant. You could lift the plant without soil around the roots, but keep the roots moist (or at least out of the sun) until replanting.

A foggy environment has good and bad effects. Fog will help to keep the rose from drying out, but it will also promote various diseases, e.g., mildew, black spot, rust. The best strategy lis to select disease-resistant roses. Here’s a link to a Sunset magazine article, “Roses for Foggy Coasts,” with a list of rose recommendations.

The article recommends seeking advice from members of the local rose society. The Monterey Bay Rose Society has several members who are qualified Consulting Rosarians, and generous with their expertise.

Irrigating with Soft Water

Q. I have a master gardener type question. In an effort to save water here in our Opal Cliff Drive home (we are part of Soquel Creek Water District, very hard water), we have to have a water softener which helps a lot. People keep on talking about using your water inside to water plants etc. I’ve always been told that soft water cannot be used for watering plants, lawns etc.

Also, we asked a water storage person who puts together rain catchment systems and were told you have to have a certain amount of space for the canisters, piping etc.. Our tiny tiny beach area yard has little space and can’t do that.

The other day in the San Jose Mercury/News the profiled a woman who is in the water business who says no space is needed and you can use soft water on your plants, that it is the best. I don’t want to kill my plants. I think everyone has different situations and so far we’ve been able to conserve our water usage by almost 25%, lost all we can do.

So you can see the concern.

March 2014

A. I asked Golden Love, a friend who installs gray water system, for an expert opinion. He wrote “When setting up gray water systems, we ask people to change their water softeners to citrus based model. Sodium used in the softeners is harmful to soil and plant life.”

Here is a link to his website, Love’s Gardens.

Amaryllis Problem

Q. The leaves of my Amaryllis is becoming curled and spotted I found some mealy bugs could this be my problem I took alcohol and cotton swabsto it but several weeks ago but the leaves are limp and spotted.

Succulant%20003Any suggestions?

Thank you as you have helped me in the past

May 2014

A. The photo you provided suggests that the plant does not have an insect pest problem, but the mosaic virus, which is not curable.

“When amaryllis contracts the mosaic virus, its leaves take on a blotchy look with yellow to red streaking. Over time, the virus will reduce the vigor and growth of the plant, and the leaves may die. Once the amaryllis has the virus, there is really no cure for it, although symptoms may worsen or improve depending on the season. To prevent the spread to other susceptible plants, remove and destroy infected plants right away.”

The above information is from an article, Growing the Delightful Amaryllis, by horticulturist Ronald C. Smith. The full article is available online from the North Dakota State University.

I’m sorry to report bad news, but it looks like time to get another amaryllis bulb.

Reply. Not the news I wanted to here but as you said get rid of them and their was 13 big red and pink. Hope it didn’t get into these last 5.

Thank you again as I wouldn’t want to lose anymore especially the Aztec Lily that has been around for over 50 years. It belonged to my Mother.

Again many thanks.