Ask the Garden Guru



Plants for sandy soil

Dear Garden Guru,

What plants would you suggest for sandy soil in the inner sunset?

Pat in San Francisco

Hi Pat,

Sandy soil and a tad of salt wind, nothing like it!

Perennials that work are: Lantana, Euphorbia, Centranthus, Erigeron, Santolina, Phormium, Pelargonium (Martha Washington and Zonal Geranium), Limonium perezii (Sea Lavender), Armeria, Artemesia, Agapanthus, Echium, Lavender and Argyranthemum (Marguerite Daisy)

Suitable shrubs are: Rosemary, Westringia, Pittosporum tobira and Pittosporum tobira Wheelers Dwarf, Coprosma, Cistus, Hebe, Escallonia, Rhus integrifolia (Lemonade Berry), Melaleuca, Leptospermum, Correa and Dodonaea.

Trees are: Metrosideros, Arbutus, Myoporum laetum standard. Eucalyptus will also work but you don’t need the mess.

Fall Fertilizer questions

Dear Garden Guru,

What is the best fall fertilizer to use for everything from fruit trees, roses, to flowers? How often should I fertilize over the winter?

Gary in San Anselmo

Hi Gary,

Fall fertilizers are not high in nitrogen. Historically, the use of 0-10-10 or Alfalfa meal has been recommended to provide a boost to plant’s immune system to combat the ravages of coming cold weather and subsequent fungal diseases. The best practice after this is mulching or top dressing with a manure or Forest Mulch Plus (the Plus is chicken doo). Do not apply a mulch to fruit trees as this will hold excess moisture in the ground around the tree which is harmful. Don’t feed plants over the winter as this encourages new growth that can be killed by frosts. The only exception would be annual flowers such as primrose, pansies and cyclamen which are actively growing in winter.

What do I grow in my container garden during the winter months?

Dear Garden Guru,

I'm from the midwest, where the winter snow prevents people from growing year round. Now that I'm in San Francisco, I have no idea what to grow in my container garden in the winter months. Any suggestions for what do on my patio from October-March would be most helpful to this midwest gardener!

Courtney in San Francisco

Hi Courtney,

You are in for a treat because the fall/early spring gardens are fun.  Annuals that are available in September are stock, pansy and viola, snapdragons, paludosum daisy, and Iceland poppy.  The snapdragons and poppy will look there best in early spring  but are best established in the fall.  The others will give you color even in the winter months.  Arriving in October are primrose, ornamental cabbage and kale, and Cyclamen.

If you want to grow some edibles,  lettuces, peas, broccoli, kale, Brussels’s sprouts and chard are available as starts, or you can start from seed.  Best from seed are onions, carrots, beets and other root vegetables.  Herbs such as parsley, thyme, sage and rosemary can be planted.  Of course, our full selection of spring flowering bulbs are available in September.  Bulbs over planted with violas work very nicely in pots.  October is also the best time to plant sweet peas, foxglove, and California poppy.  There are also fall garden mums!   There’s a reason this is such a popular state.

How to amend soil?

Dear Garden Guru,

We have your basic clay earth in our backyard. I want to amend the soil. What would you recommend I amend it with? Just regular planting mix that you sell? Or should I add lime or some other soil additives like chicken manure.....what is your secret recipe? And is it better than the Colonel's?

Bruce in Glen Park

Hi Bruce,

Forest Mulch Plus, Forest Mulch Plus, Forest Mulch Plus! This is a longer lasting blend of organic materials that also contains some chicken manure (not finger likkin’ good). This mixed with Gypsum will help break down and loosen the clay. Keep in mind that one application of any product will not change the soil indefinitely. You should get in the habit of applying the Forest Mulch Plus as a top-dressing twice a year to continue to work into the soil and help keep it from reverting to it’s natural (and heavy) state.

Gardening in sandy soil -- help!

Dear Garden Guru,

Help, I am in the outer Sunset and have very sandy soil. Can you give me recommendations on soil amendment and suggestions to plant? Thank you.

Maureen in Outer Sunset

Hi Maureen,

You have the first step right re: getting the soil amended. Indeed, there are little to no nutrients in sandy soil.

Our recommendation is to mix Sloat Planting Mix into the soil, along with E.B. Stone Sure Start when planting — this will allow plant roots to acclimate to the sandy soil, and give them the best chance to spread out and take up any nutrients in the soil.

You will need to “top dress” twice a year in February/March, and again in June/July with Sloat Forest Mulch. This is a great mix that has chicken manure and bark to help hold in moisture and keep nutrients in the soil.

Plant recommendations for your soil: lavender, sage, achillea, erigeron, Ceanothus, all cacti and succulents, escallonia, Festuca and rosemary.

Also see our Mediterranean style plant list- this should offer a good selection of options.

And a link to all our soils –

Container flower recommendations

Dear Garden Guru,

We just moved from the east coast. What container flowers/plants do you recommend for a west facing deck?

Karen in SF

Hi Karen,

aeonium_arborescens_tip_top-jpgWelcome to the Bay Area and away from east coast winters. The only issue is what you can’t put into containers. There is a vast array of plants to choose from. My favorite go-to plants are succulents. I like to choose Aeoniums for height, echeverias, kalanchoe paddle plant and Crassula for a bushy shape and then sedums, sempervivum, senecio and ice plants to trail over.

For color, I like to go with lavenders, salvia, kangaroo paws, agastache and lotus or calibrachoa to trail over. These are drought tolerant as well. Use a large pot and soil moist granules for less watering. An added bonus is that most of the plants for color attract hummingbirds. You can even mix the succulents with colorful plants; all like the same light and have similar watering requirements. Hope this helps.

How do I protect plants when temperatures drop?

Dear Garden Guru,

It's getting cold at night and some of my plants have succumbed to cold temperatures. How can I protect my plants when temperatures drop?

Sam in Albany

Hi Sam,

Protecting plants from frost can be quite easy. Twenty minutes of work on an evening when frost is expected will save many plants. The secret is having the materials you will need on hand and ready – burlap, micropore plastic (row cover sheet or weedblock), insulating blanket, shredded or bark mulch, and Cloud Cover antitranspirant.

Make sure plants are well watered. The air temperature above moist soil is about 5 degrees warmer than
over a dry soil. Spray your plants liberally with Cloud Cover. It slows the rate at which plants lose water to the surrounding air, preventing drying and wilting.

Move container plants under an eave or put them in the garage. If you choose not to move them, protect them like in-ground plants as follows: Cover the sensitive plants with a porous, lightweight covering. Freezing air flows over the cover and the unfrozen soil beneath buffers the cold. Beneath the covering, air temperatures may be 8 degrees warmer the first night of frost and 5 degrees warmer on succeeding nights. You can safely leave the covers on for one or two cool days. Remove the covers if the days warm up and re-cover at night should the threat of frost continue. If using non-porous vinyl or plastic sheeting must be supported so it does not touch the foliage (they have a tendency to supercool the plants and will freeze them.)

If you have already applied a mulch around your plants, it’s simple to heap the mulch closer to the main stem of the plant for added insulation. (Be sure to remove the added mulch from around the crown after the frost is over.)

Read our full handout on frost protection and frost recovery here.

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.  Thank you for choosing to garden with us!

Lawn Care – Native sedge lawns

Dear Garden Guru,

We would like to grow a lawn of native sedge grass that won't need much watering. What is the best type of sedge for the kind of lawn that kids can play on? How do we approach the planting process? Is it better to use seed or plugs? Obviously a sod would be a quick planting process, but I don't think that is an option. Or is it? Cheers.

Jennie in San Francisco

Hi Jennie,

Native sedge lawns really are a great solution to the common lawn but you are right, they can’t be planted by seed or sod. They are planted by plugs on 10″-12″ centers on the diagonal. Sloat does not have a vendor that supplies native grass plugs but there are 2 local reforestation nurseries that sell to the public. They are Bay natives in San Francisco ( and Elkhorn nursery ( John Greenlee , the grass guru, also sells plugs on on his website They are not inexpensive (about $2.00 a piece). John Greenlee also has a new book out about how to plant a native meadow lawn.

The variety best suited for our area is California meadow sedge, Carex pansa. In general preparation for planting plugs is similar to that for seed or sod. Remove weeds and old lawn completely, add organic amendment such as Forest Mulch Plus (found at your local Sloat store) and roto-till, install irrigation (now is the time to do it right), apply a pre-plant fertilizer such as Sure Start, rake smooth. I hope this helps you in your quest. Good Luck!

Do bulbs need to be refrigerated?

Dear Garden Guru,

I have dozens of bulbs for fall planting. I've learned I have to refrigerate the crocus, hyacinth and tulip bulbs, but I'm getting mixed messages on refrigerating daffodils in Northern California. Do daffodil bulbs need to be refrigerated in this area? Anything else I should or shouldn't refrigerate? (I know about not keeping fruits in the fridge with the bulbs.) Thanks!

Susannah in Kentfield

Hi Susannah,

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

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