Ask the Garden Guru

Fruit Tree Planting in Winter

Dear Garden Guru,

I would like to plant fruit trees this winter but I live very close to the ocean, with lots of summer fog. Which fruit trees would you recommend for my microclimate?

Melissa in San Francisco

Hi Melissa,

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!  Many of these will be available later in the season. Call our stores with any stock questions!

Removing Oxalis from the Garden

Dear Garden Guru,

I have very abundant Oxalis in my garden beds. Our neighbors have been spraying weed killer every now and again to keep it at bay. They haven't planted the beds and stopped the weed killer when we told them we wanted to plant the beds. (I want to plant vegetables and flowers including, bulbs, and sweet peas along the fence). Any thoughts of how to get rid of Oxalis? The two beds are 15 x 5 ft. -- Nalani in San Francisco

Nalani in San Francisco

Hi Nalani,

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.

What is the best time to plant bulbs?

Dear Garden Guru,

When is the best time to plant tulip bulbs?

Pat in San Francisco

Hi Pat,

Dear Pat,

Our selection of tulip bulbs is available in the fall. It’s best to have all bulbs in the ground by Thanksgiving. Bulbs are available at most Sloat Garden Center locations.

Read more about planting bulbs here:

Growing sweet peas

Dear Garden Guru,

When is the best time to plant Sweet Pea starts? When can I find them? Thanks!

Lisa in Novato

Hi Lisa,

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.

Aphids on succulents: help!

Dear Garden Guru,

What is the best way to get rid of aphids from my succulents? They are only damaging a couple varieties but the ones damaged are pretty bad. Thanks

Hunter in San Francisco

Hi Hunter,

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.

When to Prune Hydrangeas?

Dear Garden Guru,

I have Hydrangeas and would like to have beautiful blooms each year. When should I prune it?

Connie in the East Bay

Hi Connie,

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.

Squirrels eating my Squash

Dear Garden Guru,

Squirrels destroyed my container squash plants last summer. Any suggestions for keeping them away?

Julie in Millbrae

Hi Julie,

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.

Hydrangea isn't blooming

Dear Garden Guru,

My hydrangeas are getting lots of leaves and no buds!! Last year there were not as many flowers as in previous years. They are established -- one was planted 10 years ago, and the other 5 years ago. What's a girl to do?? Thank you!!

Deborah in San Anselmo

Hi Deborah,

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.

Tomato plant troubleshooting

Dear Garden Guru,

My tomato plants always look beautiful when I get them in the ground. I water and fertilize and then right after the plants flower they turn yellow and spindly and they don't fruit very well. What am I doing wrong?

Liz in San Bruno

Hi Liz,

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!

Planning an herb garden

Dear Garden Guru,

I am envisioning a small, kidney shaped herb garden right on our front lawn. I'm thinking about a raised bed, nothing too complicated, probably borders of some kind of stone or hardscape. What sort of herbs grow best in our climate? And can you offer any process insight in design?

Eric in San Francisco

Hi Eric,

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.

Curious if we have your favorite plant or product in stock? Call one of our locations directly and we'll be happy to check.