Today’s column may cause confusion.

It will contradict many long held beliefs and an ocean of instruction and tutoring, delivered in books, magazines and most everywhere else.

Today’s column is for the advanced gardener. That said, you may want to stop here and read no further. Proceed at risk; the risk of turmoil in your garden convictions. Continued reading will leave you with questions, not answers.

Ron Vanderhoff

In gardening, as in many fields, it is easy to make sweeping statements. “Water in the morning”, “Plant in the fall”, “Fertilize regularly”, “Provide good drainage” and “Add organic matter” are common declarations that are drilled into a gardeners psyche from the inception of plant cultivation. Eventually, sweeping, repeated statements become truisms, adhered to without question.

But at least one of these truisms is becoming less true – in specific instances.

For the past several years the gardens of southern California have been drifting toward Mediterranean plant palettes. Boxwoods are giving way to lavenders, birch trees to olive trees, ivy to rosemary and foxgloves to salvias. Subtropical plants are yielding to desert plants. Agaves and aloes abound. California’s native plants have migrated from wild hillsides and into our gardens. Although this garden evolution (or revolution) is subtle and in its early incarnations it throws into question a long held gardening truism, “Add organic matter”.

Maybe not!

succulents in garden

If you’re still reading and prefer the simplicity of blanket statements, it is at this point in the column that you’re going to become confused and bewildered. Turn back now – please.

Let me break down the statement “Add organic matter”. For the huge majority of plants that we have historically cultivated in our local gardens this is a very accurate statement. If you’re planting roses, geraniums, tomatoes, petunias, camellias, star jasmine and thousands of other plants that are accustomed to rich organic soils, lots of summer water and high fertility, stop reading. Keep adding mulch, compost and planting mix to your soil – lots of it. In fact double what you’re now using, especially as surface mulch; it probably isn’t enough.

But, if your plant choices have drifted toward plants of Mediterranean origins and from arid climates, the addition of organic matter may not be the way to go. In fact, a rich loamy soil, full of compost, may by quite unhealthy for these plants.

Most truly Mediterranean and arid climate plants prefer “lean” soils, those that are low in organic matter and low in fertility.

Confused yet? It’s going to get worse – don’t say I didn’t warn you.

The danger in a discussion of soil and plants is that Mediterranean plants installed into clay soils have as much chance of survival as a California oak in an Amazon rain forest.

Recently, I installed a new succulent garden at my home. Into the area, about ten feet by twenty-five feet, I added 46 hundred pound bags of sand – and no organic amendments. The sand that I added wasn’t just any sand; it was #16 silica sand, a very specific type. Only very coarse “sharp” sand should be added to clay soils. All-purpose sand or builder’s sand will create a huge mess in your soil. I know you’ve been told repeatedly, “Never add sand to clay soil”. Don’t believe everything you hear; we’re destroying some “truisms” in this column.

The soil I was heavy clay when I began. I blended the sand very thoroughly with about four to six inches of the soil and planted. Good soil for a succulent garden, lean and well drained.

I’m preparing another area for low water shade plants and I just finished adding another 20 bags of the same sand. This fall, if my back holds out, I’ll prep another area where I plan to blend native and Mediterranean plants. I’ll be adding a lot of decomposed granite for this project, and again very little, if any, organic amendments. Just what these plants want!

In a separate portion of my garden I’m growing subtropical plants; lots of epidendrum orchids, bromeliads and cane begonias. In these beds I used no sand, they were filled with almost pure organic amendments to create a very rich soil suitable for what these plants want.

If you’ve made it to the end of this weeks column and are more puzzled that when you began, don’t say I didn’t warn you. The lesson of this week’s column is to match the soil to the plants. Plants that need rich, organic soils should get exactly that, plants that want lean soils should also get what they want. Simple as that. Beware of sweeping statements.  

Ron Vanderhoff is the Nursery Manager at Roger’s Gardens , Corona del Mar.

Questions from Readers July 4th.

Question: Do I still have time to plant pumpkin seeds in time for Halloween?

Mary, Newport Beach

Answer: Hurry. In Orange County I usually suggest that pumpkin seeds by started no later that July 4 for Halloween fruits. It this time I would suggest either buying started plants or growing a smaller fruited variety, such as ‘Sugar Pie’, ‘Orange Smoothie’ or ‘New England Pie’.

Plant Care Reminders

Orchid as a Houseplant
House Plants Carole McCray

The Orchid as a Houseplant

Orchids are often stereotyped as the Mother’s Day corsage or as an adornment on the wrist of a prom date.
Fucshia hybrid Monthly Plant Care Reminders
Shrubs Julie Bawden-Davis

Fuchsia (Fuchsia hybrida) - Monthly Plant Care Reminders

You can have these monthly Plant Care Reminders sent directly to you each month!

Platycerium bifurcatum (Stag Horn…

13661 Walter Andersen Nursery
Platycerium Monthly Plant Care
You can have these monthly Plant Care Reminders sent directly to you each month!

Citrus & Avocado Tree Planting and Care

27799 Walter Andersen Nursery
Citrus & Avocado Tree Guide
Citrus and Avocado trees are well adapted to most areas of San Diego County, from the…

Plant Care Reminders List of Links By…

6383 Super User
Plant Care Reminders List of Links By Botanical Name. We have monthly regional plant care…

Gardening Articles

Calochortus pulchellus 'Mt. Diablo'
Places Ron Vanderhoff

Traveling through Nature’s Gardens, a Botanical Odyssey

"I only went out for a walk, and finally concluded to stay out till sundown, for going out, I found, was really going in." John Muir
Art Goes Wild
Landscape and Design Kathleen Hassinger

APLD International Landscape Design Merit Award Winner W Gary Smith - Specialty Project Design

Association of Professional Landscape Designers Announces: Annual International Landscape Design Awards Program Winners

Ken Andersen - Southwest

Ken Andersen
Region: Southwest

Gardening Crossword Puzzle #1

Flowers Crossword Puzzle
Print this and take a few minutes and have some fun trying to figure this crossword…

New Palm Pest Garnering Much Attention

Red Palm Weevil
Earlier this month I reported on the discovery in Laguna Beach of the world's most…

Plant Recommendations

Jim Threadgill
Plant Recommendations jim threadgill

California Natives - Southern California

Jim Threadgill's Top Plant Recommendations: Favorite California Natives.
Cassia leptophylla
Plant Recommendations walter andersen

Trees for Southern California by Walter Andersen

Walter Andersen's Top Plant Recommendation: Favorite Trees for Southern California. 

Citrus Fruits - Southern California

7999 Richard Frost
Eureka lemon
Richard Frost's Top Plant Recommendation: Favorite Citrus Fruits for Southern California.

Trees - Southern California by Tom…

11745 Tom Piergrossi
Tabebuia ipe
Tom Piergrossi's Top Plant Recommendation: Favorite Trees for Southern California.

Carnivorous Plants - Southern California

Janet Wanerka
Janet Wanerka's Top Plant Recommendation: Favorite Carnivorous Plants for Southern…

Featured Plant Care

Bearded Iris

Iris germanica - (Bearded German Iris) - Monthly Plant Care Calendar

You can have these monthly Plant Care Reminders sent directly to you each month!
Monthly Plant Care Reminders

Plant Care Recommendations - Edibles - Sunset Zone 24

in Edibles
Do you live In coastal southern California? Do you grow any of these plants?
Baseball Field Maintenance

Baseball Field Maintenance - A General Guide for Fields of All Levels

in Lawn
More great baseball field resources can be found here (including a pdf version of this…

Latest Articles

Peach Leaf Curl

Peach Leaf Curl - Information Hub

Peach leaf curl is a common problem found on leaves of Peaches and Nectarines (and their…
Avocado Information Hub

Avocado - Growing and Plant Care Information Hub

in Edibles
We're bringing relevant information about Avocados (Persea americana) to one fantastic…

Popular Articles

Using the Mulch for Home Gardeners

Home Gardener: Using All The Great Features on the Mulch

You Can Use The Great Features on the Mulch For Free!
Baseball Field Maintenance

Baseball Field Maintenance - A General Guide for Fields of All Levels

in Lawn
More great baseball field resources can be found here (including a pdf version of this…
Queen Palm Care & Use

The Queen Palm (Syagrus romanzoffiana) Care & Use

in Trees
Jungle Music Palms and Cycads is a family owned and operated business established in 1977

What are Microgreens and How to Grow Them

in Edibles
Microgreens are tiny leafed vegetables that are grown from seed and require very little…

User Guides (Slide)

Popular Recommendations (Slide)

Upcoming Events

View All Events

Who's Online

We have 6393 guests and no members online