Ask the Garden Guru

Our Garden Guru is on vacation. Please check back with us with your question after July 4th. Thank you!

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 in January or by special order later in the season.

Fall Foliage in the Bay Area

Dear Garden Guru,

Being from upstate New York, I really miss the fall colors. I recently traveled to Portland and noticed some trees there were alive with fall foliage. Can I grow such trees and enjoy the same bright colors every fall here in S.F.? And, if so, what are the bright yellow, red, reddish pink and orange trees I see. Also, what vine grows up the trees and turns red each fall?

Lee in San Francisco

Hi Lee,

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.

Tree Watering

Dear Garden Guru,

I have a 2 year-old Stella cherry tree and a 3 year-old Santa Rosa plum tree. I just installed drip watering, had been just soaking with a hose, pretty irregularly. Surprised they have survived me. How many gallons per soaking (and how often) should I be giving them in each of the four seasons here in Novato?

David in Novato

Hi David,

Trees are remarkably forgiving things. Your trees will not need irrigation in winter once the rains start and will not need to be irrigated until the weather warms up. The first irrigation in spring is about 2 weeks after the last rain once the tree has blossomed and “woken up”. At this point, the 2 year old will need about 2 gallons/day and the 3 year old will need 4 gallons per day. Once mature, the plum will need 6-12 gallons/day depending on the time of year and the cherry will want 20-45 gallons per day! The higher gallonage reflect its needs in the hot summer months, the smaller is for spring and fall. Because our soil is so very clayey in Novato, it will hold more moisture for a longer period of time. If you were to irrigate everyday, there is a chance you could over water. I would recommend you water with drip every 3rd day. For instance on the 2 year old, if you use 2, 1 gal emitters and water for 1 1/2 hours, the tree gets 3 gallons every 3rd day. If the trees seem to wilt or “loose their shine”, you can water more often (for less time) or use more emitters per tree.

Buying a Meyer lemon tree

Dear Garden Guru,

Hi, I would like to buy a Meyer lemon tree in October as a gift, do you think they will be available. -Much Thanks

Dana in San Francisco

Hi Dana,

Yes, our stores will continue to stock Meyer Lemon trees throughout the Fall (Subject to availability). We sell quite a few during the entire Holiday Season, so we maintain our supply year-round. The only potential for not having them is some type of crop failure from our local suppliers.

Feel free to call ahead to your local store just to be sure. And, as always, if they are out of stock you can certainly place a “special order” for one.

Outdoor potted trees

Dear Garden Guru,

We need two large outdoor potted trees in the front of our north-facing building on Russian Hill. We want to replace the privets that are there now. What is a good choice? Do you pot large plants and deliver same to SF addresses? Thank you.

Ann in San Francisco

Hi Ann,

You can consider any of the following trees for containers in the city. Please note that exposure is a vital key to any tree’s success. A north facing building can offer many different types of light, dependent on surrounding structures. Please verify the amount of direct sun the area gets when you are speaking with one of our team members at the store. Availability will vary from week-to-week and most likely, we will need to place a special order. The store can fill you in on transplanting and delivery fees (dependent on size of pot and distance of delivery). All of these trees are proven winners in San Francisco:

  • Brugmansia
  • Lemon tree
  • Laurus nobilis
  • Japanese maple
  • Dodonea viscosa
  • Osmanthus fragrans
  • Arbutus unedo
  • Leptospermum
  • Thuja

Japanese Maple Care

Dear Garden Guru,

What is the best way to care for a newly planted Bloodgood Japanese Maple? The leaves on mine are curling and becoming brown - is it getting too much sun? I'm in a foggier part of SF. Thank you.

Maria in San Francisco

Hi Maria,

Japanese Maples need protection in San Francisco.  They are quite susceptible to wind and salt burn.  They prefer to be planted on an eastern exposure that receives some morning sun and protection from the wind.  If you are within a few blocks of the ocean, you can expect salt burn on Japanese Maples regardless of the exposure or protection.

I would recommend that you bring a sample of a few leaves into one of our stores just to ensure that the damage you describe is from wind or salt.  There are other ailments that they can get.

Holly Trees

Dear Garden Guru,

Hello! I have a quick question re: Holly. For 59 years my family's holly tree has produced red berries in December. For the last 2 years it has produced berries in September. Do you have any information to why this is happening? is it climate change? Thanks for your help! Our Christmas just isn't the same without grandma's holly over the fire place!!

Kelley in Larkspur

Hi Kelley,

The berries of English Holly do naturally start to ripen in September on the sunniest side of the shrub and are completely ripe by late October. The berries should still look fresh and ripe in December for the holidays. As you haven’t used the berries now for 2 years, I am assuming that they don’t look good anymore, have shriveled or blackened by December. Beyond climatic change, which does seem to exist as we have seen fall symptoms in our surroundings in early August for the last few years, it could be that the holly is receiving more sun. Has a tree or screen been removed?

We also have had very hot or dry summers the last 2 years. Is the holly being watered regularly in hot dry weather? Lack of adequate moisture can cause berries to shrivel. Plants in full sun can sunburn (Blacken) when temperatures soar. I suggest you keep your plant irrigated to keep the berries looking fresh, once the temperatures cool, those berries should last.

I hope this helps. As always feel free to visit any of our Sloat locations for more expert advice!

Dwarf Citrus Trees

Dear Garden Guru,

We have a dwarf citrus tree that I planted last winter. It is green and growing nicely. It has flowered several times, but when the fruit begins to form, it gets to the size of a ladybug and then turns black. What is happening?

Kim in San Rafael

Hi Kim,

It is normal for citrus,especially young ones, to shed small fruits. The plants always seem to set more fruit than the trees have energy to provide for. Sometimes, as much as 3/4 of the fruits will abort! Usually, the fruit will fall when still green, or it will get yellowish first.

The fact that your small fruits are turning black first indicates that you are either over watering or they are getting infected with a bacterial disease. The bacterial disease would develop in a situation where the tree was getting overhead sprinkling. It also could spread to the leaves, but you say the leaves look great. I suspect the watering more but to be sure, you may want to spray your tree with EB Stone Copper Soap. This is an organic spray that kills and prevents fungal or bacterial diseases.

I hope this helps get you started on controlling the issue. As always, feel free to visit any of our Sloat locations for more expert advice.

Leaning Cypress Trees

Dear Garden Guru,

Help! With this latest wind and rain one of my 20 Italian Cypress has leaned over so far and I am unsure how to restake it. Should it be dug up and restaked or can I just pull it back upright?

Valerie in San Mateo

Hi Valerie,

I’m not sure if you are asking about a 20 foot tall cypress or 20 individual cypress trees.  Assuming it is one tall tree, the best avenue would be to try and straighten the tree up while the ground is still soft. The tree will be difficult to dig up as a tree that size will have a substantial root mass.  Two 6-8 foot stakes driven into the ground on the wind side of the tree should be sufficient to stabilize it.  Use a galvanized, braided wire to attach the tree to the stakes.  A short piece of hose or rubber tubing will protect the trunk of the tree from the wire.  Be sure to attempt to pull the tree upright by applying pressure low on the trunk.  If you push or pull too high, you run the risk of breaking the trunk.  If you feel this process is beyond your capabilities, I would highly recommend that you contact a garden professional or tree specialist.

Fruit tree selection and care

Dear Garden Guru,

I live in SF - Richmond district near Park Presidio Blvd. What kind of fruit tree would you recommend for this area other than apple and pear which I already have? Also, I have Winter Nellie pear, D'Anjou pear and Red Delicious apple trees in Richmond district of SF. When and what should I spray the trees. 2008 I had caterpillars on the pear trees eating up all the leaves and would like to avoid them, if possible.

Jane in San Francisco

Hi Jane,

If you want another type of deciduous fruit tree consider a Santa Rosa or Beauty plum. Apricots can also be considered if your yard is really warm and sunny. Of course, all types of Citrus will also do well for you : Trovita orange, lemons, limes and Mandarins. You can spray the trees now and again in mid February with Kop R Spray to prevent diseases such as powdery mildew and scab. To treat for caterpillar, wait until 3/4 petal fall (when 3/4 of the flower petals have dropped off the tree). By then, the young leaves will be pushing. Spray with BT caterpillar killer at monthly intervals or after heavy spring rain. This is a harmless spray to non target insects such as bees and other wildlife.

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