Tag Archives: soil

What’s in your Soil?

“The soil is made of butterfly wings, dinosaur teeth, pumpkin seeds, lizard skins, and fallen leaves.
  Put your hands in the soil and touch yesterday, and all that will be left of tomorrow shall return
  so that new life can celebrate this day.”  -Betty Peck

Soil makes all the difference to the plants you grow. The biggest issue we gardeners face is the ongoing battle with soil. If yours is difficult to manage or just plain unproductive you’ll be disappointed like me with the performance of many of the plants you put in the ground. Even tough plants like California natives have soil preferences and they are not always what’s in your garden.

phormium_acorus_lomandra
Low water-use plant responding to fertile soil

We live on ancient sea cliffs.  Soils in Bonny Doon and Scotts Valley consist of shallow, excessively drained weathered sandstone and shale. Felton soils were formed from shale, sandstone or mica schist. Those in Ben Lomond and Boulder Creek had their beginnings from weathered sandstone or granite. Although these provide the necessary mineral component of our soil. organic matter or humus from decayed plant and animal material are necessary also for fertility.

Here’s why improving your soil will make a difference to the health of your plants.

Good soil-with both organic matter and minerals-helps plants grow by forming the food supply for soil bacteria that help make food available for plant growth. Most of a plants energy goes to producing substances that drip out through the roots to attract bacteria and fungi. These in turn attract good nematodes and protozoa to the root zone. The protozoa eat bacteria and the nematodes eat not only the bacteria but also fungi and other nematodes to get carbon. What they don’t need they expel and this feeds the roots much like earthworm castings.

Down in the soil, if a plant needs different foods it can change what is secretes. Different substances will attract different bacteria, fungi, nematodes and protozoa. This huge diversity of soil biota helps the good guys keep the bad guys in check.

A common way to destroy the microbiology of the soil is to add salts in the

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Collection of perennials one year after planting in amended soil.

form or non-organic fertilizers. The salts kill the bacteria and fungi by dehydrating them. Then the plant can’t feed itself and becomes dependent on its fertilizer fix. Without the good bacteria and fungi in the soil other parts of the food chain start dying off as well.

The soil food web is also responsible for soil structure. Bacteria create slime that glue soil particles together. Fungi weave threads to create larger soil particles. Worms and insects distribute bacteria and fungal spores throughout the soil and create pathways for air and water.

What can you do to bring your soil back to life?
• Mulch around perennials, shrubs and trees with 2-3” of compost, wood chips or other organic mulch.
• Apply mycorrhizal fungi, especially in a new garden that’s been rototilled or chemically fertilized. You can find this in most organic fertilizers and some organic potting soils.
• Try to avoid walking on the root zone of plants. This kills fungi in the soil. Install stepping stones to preserve soil structure.

Feed your soil- not your plants.

What to Plant in Clay Soil in the Santa Cruz Mountains

              "The soil is made of butterfly wings, dinosaur teeth, pumpkin seeds, lizard skins, and fallen leaves.
                  Put your hands in the soil and touch yesterday, and all that will be left of tomorrow shall return
                                         so that new life can celebrate this day."  -Betty Peck

Soil is a wonderful thing. It grows our food, anchors our trees and provides a foundation under our feet. But it sure can be hard to work with if it’s not the soft, crumbly loam that many plants prefer. It’s amazing that anything grows in some of the soils here in the Santa Cruz mountains. Some folks garden in an ancient sea bed of sand and there are others who have such heavy clay in their gardens that you wonder how anything survives.  Recently I helped plant in the dense clay of Garrahan Park in Boulder Creek and I dedicate this column to those of you with similar inhospitable soils.

The soil in Boulder Creek required a pick ax to break up enough to plant. Sound familiar?  Although rich in nutrients it needed compost in many areas to provide the environment  necessary so beneficial microbes, worms and other critters could do their work and aerate the soil. A thick layer of mulch will be spread over the soil by The Boy Scouts to preserve the structure and prevent it from packing down again.

There are many plants that are tolerant of clay soils and plant selection is half the equation. The park chose mostly California natives that won’t need fertilization or pruning, can be eventually weaned from irrigation and will provide food for the birds and visiting children. Juncus, a type of grass, red-flowering currant, redtwig dogwood, California rose and western redbud will be the stars of the park in the wet, clay soil. The drier side of the park was planted with deer grass, toyon, California rose, huckleberry, coffeeberry , ceanothus, native honeysuckle, vine maple, native iris and California fescue grass.

I’m sure the park will be the crown jewel of the area and hopefully you will come to visit and see the progress of the plants. Kinda like a local demonstration garden in the San Lorenzo Valley.

There are plants from similar environments in other parts of the world that would also do well if you garden in heavy soil. One of my favorite trees for these conditions is the strawberry tree. Also hackberry, ash, gingko and paperbark trees work well also. Shrubs to try include flowering quince, bottlebrush, Australian fuchsia, smoke tree, escallonia, pineapple guava, mahonia, osmanthus, Italian buckthorn, elderberry and vitex. Easy perennials for clay soils are yarrow, bergenia, carex grasses, fortnight lily, coreopsis, echinacea, nepeta, salvia, teucrium and verbena to name just a few.

If you’re not familiar with some of these plants it’s easy to see what they look like by Googling images. It’s what I do to see a plant full grown and not just a line drawing or a close-up of the flower.

So you see, there are plants that will be successful even in heavy, clay soil, you just have to pick the right ones.

Taking Care of your Soil

Gardening is all about dirt-its care and feeding, its microbes and fungi, bacteria and earthworms. So whether you’re planting your vegetable garden or a border of perennials, feed the soil- not the plants. Start by using organic fertilizers and pesticides. Here’s why.

Most of a plants energy goes to producing substances that it drips out through the roots to attract bacteria and fungi. These in turn attract good nematodes and protozoa to the root zones. To make a long story short, the protozoa eat bacteria and the nematodes eat not only the bacteria but also fungi and other nematodes to get carbon. What they don’t need they expel and this feeds the roots much like earthworm castings.

It gets even more interesting down in the soil. If the plant needs different foods it can change what is secretes. Different substances will attract different bacteria, fungi, nematodes and protozoa. This huge diversity of soil biota helps the good guys keep the bad guys in check.

A common way to destroy the microbiology of the soil is to add salts ( non-organic fertilizers). The salts kill the bacteria and fungi by dehydrating them. Then the plant can’t feed itself and becomes dependent on its fertilizer fix. Without the good bacteria and fungi in the soil other parts of the food chain start dying off as well.

The soil food web is also responsible for soil structure. Bacteria create slime that glue soil particles together. Fungi weave threads to create larger soil particles. Worms distribute bacteria and fungal spores throughout the soil and create pathways for air and water.

What can you do to bring your soil back to life? 

  • Add 1/4" of compost on top
  • Mulch around perennials, shrubs and trees with dried leaves and grass clippings for annuals.
  • Use aerated compost tea
  • Apply mycorrhizal fungi, especially in a new garden that’s been rototilled or chemically fertilized. You can find this in most organic fertilizers and some organic potting soils.
  • Try to avoid walking on the root zone of plants. This kills fungi in the soil. Install stepping stones to preserve soil structure.
  • After employing the above suggestions if you’re looking to add something new to your newly revitalized shady border consider planting a flowering maple that bears lilac blue flowers. Abutilon vitifolium grows to 6-8 ft in partial shade. Gray green maple-like leaves reach 6" or longer. Flowers grow singly or in clusters on long stalks. Abutilons need good drainage.

    As a ground cover underneath them, grow . Vivid periwinkle blue flowers bloom spring through summer. Campanulas are a large family of perennials. Some are low groundcovers like Get Mee’s to 3 ft tall peach leafed campanulas. Both are easy to grow and are choice plants for borders.

Sustainable gardening tips

Blazing hot weather one day, foggy the next – our summer is turning out to be a particularly hot one.  The last two winters saw more than the usual freezing weather.   If weather tells us what clothes to wear, then climate tells us what clothes to buy.  Is all this proof of climate change?

Our planet has always experienced heating and cooling cycles.  A warm period from 300-1300 AD allowed the Vikings to fish and farm Greenland.  They were frozen out after 1300 when the Little Ice Age changed Greenland’s climate.  A 20 year drought starting in 1276 probably drove out the cliff dwellers in Utah, Arizona and New Mexico and the Mayan culture collapsed about the same time as an extended drought occurred in Mexico and Central America. 

People who cultivate plants have always taken climate change more seriously than most.  Many tomatoes stop setting fruit when daytime temps stay above 90 degrees.  Higher levels of carbon dioxide, a greenhouse gas, have been accelerating weed growth.  Our best defense as gardeners is to choose wisely what we plant in the garden and how we water. 

  • Start with smart design by evaluating how the space will be used and what plants will thrive with minimum of care and pruning.  Select the best trees and place them to shade the south side of the house to reduce  cooling costs.
  • Supplement the soil by making soil health a priority.
  • Examine your irrigation system and watering plan for efficiency and minimal waste.
  • Reduce, recycle and reuse whenever possible.  Simple ways include reusing plant containers and composting  organic waste and fall leaves.  

  We can all become stewards of the land by using these sustainable landscaping tips.

Garden coaching

Right plant-right place

Lately I’m getting a lot of requests for garden coaching. The economy probably has something to do with it. People want to know what plants will thrive in the different areas of their gardens or why something isn’t working. Who can afford to waste $ on the wrong plant in the wrong location?  When I make house calls there are several problems that seem to keep cropping up. Maybe one of these tips will help make your garden grow.

  Poor soil
If your soil looks like a sandy beach, amend it each time you plant something new with organic matter like compost or planing mix. Then be sure to mulch the surface to preserve precious moisture and soil structure and keep roots cool. Yearly, add organic mulch around existing planting keeping the immediate area around the crown of the plant open. If your native soil is just a little on the sandy side, you may not need to amend the soil much before planting but don’t forget that all important mulch. Crushed gravel or cobbles uses as a mulch holds in moisture the same way as bark or compost.

Those of you who live under redwoods may have the opposite problem- heavy clay soil, dense enough to make pottery. Surprisingly, adding organic matter to these soils solves this problem, too. The key is preserving the soil structure fterwards by mulching so it doesn’t pack down every time you water or during the winter rains.

 Not watering deep enough or watering too often
Sure there’s a period of time when you first plant something that you need to water more often until it’s established but even then watering every day is rarely needed. As a rule of thumb, water a new 1 gallon plant when the top 1/2 " – 1" is dry. A newly planted 5 gallon container will need watering when the top 1 1/2 – 2" is dry. A tree or large shrub planted from a 15 gallon container needs watering when the top 2-3" is dry. Hot days as well as shady locations vs sunny sites will all affect how long you can go between waterings.  When you do water apply enough to water the entire root zone deeply. If the water doesn’t penetrate 1-3 ft down, depending on the plant, it will suffer and even die. Drip systems are great if you have them set properly. Don’t waste water by having your timer set for 10 minutes every other day. If you have 1 gal/hour emitters that’s less than 3 cups of water each. How deep is that going to penetrate? Set your system so that each zone gets enough water for long enough to really count. This applies to established low-water use plants, too. They need a deep soak every 2-4 weeks.
One last tip on drip systems: make sure the emitter isn’t right next to the stem or trunk. Plants need water applied at the drip line where the feeder roots are located, not drowning the crown. Move it out as the plant grows and the dripline enlarges.

  Gopher baskets
If you need to plant in gopher baskets, make sure you eliminate the air pockets between the root ball and the side of the basket. Many times I’ve dug around a plant that is not doing well only to find big air spaces down the side of the basket or the planting hole where the soil was not properly tamped down. The roots on that side of the plant will die under these conditions and possibly the whole plants will be killed.

  Right plant-wrong place
Become familiar with the sun patterns of your property during the growing season- spring through fall. Many of us don’t have winter sun and lots of plants can adapt to this but they are more exacting when it come to light requirements during the growing season. It gets pretty hot around here so a spot with sun in the afternoon is fatal to a plant that is not a sun lover. For those optimists out there, those delicate rays that filter through your trees do not constitute a sunny garden. You have bright shade and there are lots of great plants that can provide color and texture in your shady garden. Make sure you follow tip #1 in both spots so your plant isn’t fighting crummy soil on top of everything else it has to handle.

Hopefully, these tips will help make your garden grow better.