Ask the Garden Guru

Unfortunately, the lack of thorns does not indicate whether you have a sucker or a cane.  Many rose bushes will throw almost thornless canes occasionally that produce an umbel of flowers. They are difficult to prune in that they don't always have a well oriented leaf bud scar to make a cut above.  You really do have to see if the origin is coming from beneath the bud union or the root zone. These thornless canes are often skinnier than there thorny sisters which makes it even harder to tell.  You won't be hurting anything if you feel you must remove it just to be sure.

San Francisco has a very mild climate and the degree of temperature fluctuation from night to day is very small. All those brightly colored trees require a change in weather (colder than what we have) to start the coloring process (along with a bunch of other factors that affect their biochemistry). Those multi-hued trees you see are Chinese Pistache and they require the least amount of chill to get going. Ornamental Pear and Liquidamber are two other trees for you to consider. Our customer service team members can help find them for you at any Sloat location. The vine you mention is Boston Ivy. There are two types available Partheocissus tricuspidata (3 lobed leaves-the classic) and Parthenocissus quinquefolia (5 lobed leaves). Both will change color in San Francisco, albeit later than the surrounding counties. I hope this helps you find some fall colors.

It may be that you are pruning your hydrangeas too late in the season. New flower buds for the following season are formed in the fall. These are the big, fat pairs of buds that you see higher up on the canes. The best time to prune is right after the shrubs have finished flowering in late summer. If you do prune later, prune back sparingly so that these fat buds are not all removed. Another possibility is that the site has become more shaded. Are there trees or shrubs that have overgrown into the light? Lastly, freezing temperatures can injure flower buds on hydrangea. We have had a couple cold winters back to back.

Blueberry flowers can die before producing fruit if the plants have experienced dryness or they were not pollinated. It is normal for the flower to turn brown before falling off but usually there is a forming berry behind it, mostly appearing as a flattish disc that eventually fills in. Crinkly leaves are an indication that you had aphids at some point sucking on the new leaf buds. An aphid infestation around the flower buds could also have caused them to fall prematurely. Keep your plants well watered and feed monthly with an acid formula fertilizer. The soil you provided is good. Give it some time and report back if there are still issues.

We think you have Budworms in your blooms! These caterpillars feed on the buds, flowers, and developing fruit of many plants, including tomatoes, peppers, and Petunias. They can cause significant damage, leading to loss of blooms, stunted growth, and reduced fruit production. It's best to handpick them off plants. This can be time-consuming but effective for small infestations. Also, practicing good garden hygiene by removing plant debris and regularly inspecting plants for signs of budworm infestations can help prevent future outbreaks. Insects that eat the eggs and small larvae are the minute pirate bug and big-eyed bug. If spraying is necessary, an organic control such as Monterey Bt Caterpillar Killer is recommended.

The first tip is to take care of the soil. Don't skip on the amendments that will help retain moisture and offer nutrition. Water regularly, especially the flowers and vegetables. Choose organic fertilizers that will not harm the beneficial soil organisms that help your plants' root systems by improving nutrient uptake and guarding against disease. Actinovate is a wonderful supplement for any new garden plant. Vegetables: peas, lettuces, chard, beets, cabbages, broccoli, mustard, spinach, carrots, radishes, kohlrabi, arugula (actually all your greens), in the summer- cherry tomatoes too. Herbs- parsley, cilantro, rosemary, chervil, savory, sage, thyme, oregano, marjoram Fruits: raspberries, southern highbush blueberries, apples, pears, strawberries, loquat, pineapple guava, lemon, kumquat, Trovita orange Flowers that attract beneficials and pollinators- white alyssum, cosmos, achillea, agastache, tulbaghia, Oenothera, Eriogonum (Buckwheat), Erigeron, Dianthus Hummingbirds:- Abutilon, Fuchsia, Agastache, Salvia greggii, Salvia clevelandii, Nasturtium, Delphinium There is so much more, but this will get you started.

For your foggy, coastal conditions consider Santa Rosa plum, Meyer Lemon, Persimmon, Asian Pear 21st Century, and Apricot. For something more exotic, the Pineapple guava, Feijoa sellowiana, will work. You could also consider Blueberries! Call our stores with any stock questions.

You should attempt to dig as much of the Oxalis out as possible. Mature plants have many small bulblets at the base. Sifting the soil after you have dug what you can will help capture any loose bulblets. Cover your beds with the lasagna method of mulching. First wet newspaper, then cardboard, then compost or forest mulch, then more newspaper, planting mix, cardboard, then compost. You can plant directly into your lasagna layers. Any Oxalis trying to resprout will be depressed by the mulch layers.

Alas, the best time to start sweet peas in our climate is in October. Planted in the fall, they develop strong root systems and then take off in the spring. Both seeds and starts are available. The second best time is in February. Our stores will have packs of tall-growing sweet peas available in a variety of colors.

You can control the aphids with Bonide All Seasons Oil. This non-toxic oil spray will smother both eggs and adults. Water your plants prior to spraying and apply when temperatures are 75 degrees or less.

Dear Connie, The classic mophead and lacecap Hydrangeas produce flowers for the next season in late summer and early fall.  Pruning is best done in September or October. Flower buds for the next season are seen as a pair of swelled “rabbit ears” on the stems just below this years flowers. You will want to prune just above them.

If squirrels are a nuisance, you may have to cover your squash plantings with netting. Creating a tripod of stakes around the plants and then draping the netting should keep them out.  The netting at the base should be weighted down or secured to keep them from crawling under.  Spraying Messina Squirrel Stopper around the vegetables would be the second line of defense.

Yellow and spindly tomatoes don't fruit that well do they? Believe it or not, I suspect that you are loving your plants too much. Over watering tomatoes will wash away all the nutrients you so lovingly applied, it also reduces needed oxygen in root zone and makes the plant susceptible to disease. Your plants should be deep watered 2 to 3 times a week. If the plant is seen wilting in the middle of the day, ignore it. Tomatoes will close their stomas in the heat of the day to prevent water loss by transpiration. They will perk right back up by late afternoon. If the plants look droopy in the morning, they need water. Too shady a location will also cause plants to be spindly but you usually see that effect immediately. If the leaves are showing some signs of browning, your plants may have Verticillium or Fusarium wilt. These are soil borne pathogens and there is no chemical control available. Warm and humid conditions will hasten the onset of wilt. It is highly recommended that you plant tomatoes labeled with "VF" (Verticillium/Fusarium) on the label as these are resistant varieties. Should there be an "N", that means resistant to root knot nematodes. Hope this helps for this year's crop!

Herbs that do well in your area are: Rosemary, Spanish Lavender, sage, parsley, Santolina, chive, and marjoram or oregano. Thyme and basil can be fickle. You may want to reconsider the kidney bean shape. A square or rectangle is more conducive to the classic herb knot and easier to work with. Choose plants that contrast in foliage color. After the size of the bed is decided, graph paper and colored pencils are very helpful. Each square could represent 1/4 ' so consider planting two 3" pots per foot. Use a different colored pencil for each herb. In other words, 4 squares in a row would be colored the same. It might be worth looking at some of the DIY and HGTV links or calling our Design Department to schedule a consultation. The number is 388-3754.

The Meyer lemon does very well in San Francisco.  The Eureka lemon will also grow but gives only one crop a year where the Meyer is known to produce almost year-round.  Herbs that will do in your neighborhood are rosemary, oregano, marjoram, thyme, and sage. These are woody plants and are not thirsty.  You can grow parsley, chervil, and savory but these "soft" herbs will require more water.

You do not need to refrigerate Daffodils or Narcissus. Some people keep Paperwhite Narcissus in the refrigerator to "stall" sprouting so they can force the bulbs over a longer period of time. This is probably where you are getting a mixed message. While not necessary, some people like to chill their Freesias - it seems to make the stems sturdier.

Hello! Good candidates for your purpose are:

• Podocarpus (all species and varieties: gracillior, macrophyllus, Icee Blue)
• Dodonaea ‘Atropurpurea’, the Hopseed
• Rhamnus alaternus and Rhamnus John Edwards
• Pittosporum tenuifolium

 

Those little buzzing pests are fungus gnats. They become a problem when houseplants (or greenhouse plants) are over-watered or when the soil stays constantly moist. Overly moist soil is more relevant to the gnats indoors because the temperatures stay warm. The adult gnats lay eggs in the soil. The larvae hatch and begin to feed on the decaying organic matter of the soil (and can sometimes harm roots if their numbers are great). They pupate and then emerge as the annoying gnats to start the cycle again. The cycle can be broken if the soil is kept drier, allowing more time between watering. Repotting a plant into fresh soil will also help. There is also a product called Gnat Exterminator. They are beneficial nematodes (microscopic soil dwelling "worms") that prey on the gnat larvae. They are applied as a spray to the infected foliage. Sloat also carries a miniature sticky trap, called Gnat Sticks that can be placed in the pot to trap the adult gnats.

Start by using a repellent like Bonide Mole Max (it also works for gophers). This is a castor oil-based repellent that is not harmful to animals or birds. Take extra care to apply more heavily around holes. This granular formula is easier to apply than a liquid spray. Apply the repellent gradually towards the direction you want them to leave the property, in other words, leave them a way to get out. Applying the repellent to the whole space at once will just “trap” them there. If it is really very bad, you might consider a gopher removal/trapping service such as Smith’s Pest Management which focuses on trapping over poisoning. Additional notes:

• Plants that tend to be deer resistant also have less appeal to gophers (See the plant list)
• Nothing is truly gopher "proof" and you may need to plant in gopher cages.
• Here's a link to common questions about  gophers: https://sloatgardens.com/gophers.htm