Design trends

How Plants Survive in the Heat

Growing back after the fire this California fuchsia is hoping to attract hummingbirds, bees and butterflies.

What happens to a plant when the thermometer tops 100 degrees ? Planning for more hot weather this summer is a requirement for a successful garden. Are there some plants that can survive tough times more easily?

Photosynthesis is one of the most remarkable biochemical processes on earth and allows plants to use sunlight to make food from water and carbon dioxide. But at temperatures about 104 degrees the enzymes that carry out photosynthesis lose their shape and functionality. A garden that provides optimum light and water but gets too hot will be less vigorous. Tomatoes, for example, will drop blossoms and not set fruit if temperatures are over 90 degrees. Plants that endure high heat can be stunted, weakened and attract pests and diseases even if water is available.

Plants do have natural systems that respond to heat problems. Some plants are better at this than others. Plants can cool themselves by pumping water out through the leaves for a kind of swamp cooler effect. They can also make “heat-shock” proteins which reduces problems from over heating. All these strategies do take resources away from a plants other needs like growth, flowering and fruiting.

It’s no surprise that many California natives are adapted to high temperatures. Walking my old property the other day I noted which plants are regrowing after the fire, despite little winter rainfall. Every plant burned to the ground. The climate is much hotter up in Bonny Doon now that the tree cover is gone. The redwoods are trying to regrow but it’ll be decades before they provide shade again. Those plants that have regrown the best include California fuchsia (epilobium canum). They spread by underground rhizomes so it’s not surprising they survived. I didn’t see any bees or hummingbirds around but one of these years they’ll return. Another survivor is hummingbird sage (salvia spathacea). They are just starting to regrow and were not in bloom.

The Bees Bliss Sage, a low groundcover that can reach 6-8 ft wide is another plant that I used to enjoy. It has an extended bloom time from mid-spring to early fall with whorls of lavender-blue flower spikes. Bees, butterflies and hummingbirds all find it attractive. The jury’s out whether it’ll return or not.

Another plant that can handle high temps is salvia clevelandii. Their blooming cycle of electric blue-purple flowers will last through the summer. This salvia survives without any supplemental irrigation but if you give it an occasional deep watering and wash off the foliage every so often it’s much happier.

Who doesn’t like color in their garden? Mimulus or Sticky Monkey Flower blooms are showy and the hummingbirds love them. The Jelly Bean series has added bright pink colors in addition to white, orange, red and yellow but the traditional aurantiacus types are the most tolerant of drought.

Other California native plants that can handle the heat with little water include eriogonum, manzanita, artemisia, California milkweed, ceanothus, mountain mahogany, bush poppy, bush lupine, native penstemon, monardella, mahonia nevinii , fremontodendron and holly-leafed cherry.

Non-native well-adapted plants that are known to be more tolerant of heat include butterfly bush, germander, rosemary, smoke tree, rudbeckia, coreopsis, lantana, plumbago, gaillardia, lilac, sedums, oregano and verbena.

This New Zealand tree fern although not a native is growing back after the fire with no water. Nature is resilient. I thought it deserved some recognition.

These plants can be the rock stars of your garden. Some natives that are able to survive with no irrigation after 2 years may look more attractive with a few deep waterings per summer. And don’t forget the wood chip mulch to encourage the soil microbes and keep the soil cool.

Design trends

Fun Facts from the Garden

Bob, the hosta seboldiana in bloom.

I confess, I’m not one who talks to plants. Although I have a huge hosta seboldiana named Bob as well as an offset that I cleverly named Bob the Second, I don’t address them personally. Maybe that’s going to change. I was very intrigued reading a recent article in Audubon magazine by Nathan Ehrlich. Scientists have discovered that plants give off electrical impulses in response to threats. Polygraph expert and former CIA interrogation specialist Cleve Backster confirmed this when, on an impulse, he hooked up a tropical dracaena to a polygraph and threatened the plant with a flame. The dracaena displayed the same electrical signals that people do when they lie. From lettuce to bananas, the results were similar.

Biologists Baldwin and Schultz have published work suggesting that some plants can communicate through the air. When the researchers threatened poplars and maples they found that nearby trees, with no physical contact, released defensive chemicals that inhibit digestion, thus hindering predators’ ability to consume the trees leaves or bark.

Plants have many ways to defend themselves. One common way is by being poisonous or irritating. You can get severe eye burn if you get the toxic sap from a euphorbia in them. You just have to accidentally rub some sap near your eyes to trigger a reaction that will require a trip to Urgent Care. The pain can last for days and has been described as a very painful experience. Euphorbias are very deer resistant and drought tolerant and are being used more and more in gardens. Great plant that requires respect.

Many of us are growing milkweed (Asclepias) to attract monarch butterflies. The milky sap from this plant protects the monarch from being eaten and can cause the same painful burning of the eye. I read of a case where a gardener’s clothes brushed some stems while she was tending the garden. Later she wiped the sweat out of her eyes and didn’t realize she had also touched her pants. She ended up with cornea burn causing temporary blindness and had to take strong pain relievers and steroids to elevate the pain. Yikes.

One of my favorite classes when I attended Cal Poly San Luis Obispo was Plant Taxonomy. On the surface the subject sounds a little dry but the professor was all about plant reproduction which is quite exciting and more varied than you think.

It’s fascinating to mark time with events in the botanic world. There’s even a word for it- Phenology. Websites like USA National Phenology Network offer lots of information on the subject. Visit http://www.usanpn.org/

Phenology is the study of plant and animal life cycle events and how these are influenced by seasonal variations in climate. When do they occur each year? Phenology is a real science that has many applications. In farming and gardening, phenology is used chiefly for planting times and pest control. Certain plants give a cue, by blooming or leafing out, that it’s time for certain activities, such as sowing particular crops or insect emergence and pest control. Often the common denominator is the temperature.

Indicator plants are often used to look for a particular pest and manage it in its most vulnerable stages. They can also be used to time the planting of vegetables, apply fertilizer, prune and so on. Record your own observations to start a data base for our area.at https://budburst.org/ Another great site is National Sustainable Agriculture Information Service at https://attra.ncat.org/ Sites like these can also help you design orchards for pollination and ripening sequence, design for bee forage plantings, design perennial flower beds and wildflower plantings as well as plantings to attract beneficial insects and enhance natural biological control. How cool is that?

But back to plant reproduction. Mosses reproduce from male and female mosses which produce spores. Conifers produce two type of cones on the same tree. Wind blows the pollen to another cone which combine to make a baby conifer which lives in a seed inside the cone.

Flowering plants like this Princess Flower have both male and female parts in each flower.

Then there are to most advanced plants – the flowering plants. Some flowering plants have both male and female flowers. They are monoecious meaning “single house”. Dioecious plants have male flowers on one plant and female flowers on another. Plants that rely on flowers for reproduction are very dependent on outside help such as insects and animals which is where we come in. Be a citizen scientist in your own backyard.

Design trends

Celebrating 800 Columns

The author in her old garden in Bonny Doon before the fire.

Since writing my first column in October 2005 I have shared with you, my good readers, many a gardening tip, confession, aspiration, resolution, success story and utter failure in my garden. We live and learn from our mistakes. We gardeners love to swap stories and sometimes I learn as much from you as you do from me.
We gardeners are eternal optimists. Why else would we plant a tree, a seed or a garden?

With Guatemala and Honduras in the news I recall my trip there in 2007. On Utila, an island off the coast of Honduras, I noticed plants growing in washing machine baskets. I thought it was a clever way to re-use old appliances but wondered why there were so many old washing machines on a tiny island. A local laughed and told me the baskets protect their plants from the big blue crabs that come out at night. Seems the crabs will sever the stem right at ground level and drag the whole plant into their hole. Also the baskets protect the plants from the iguanas who will eat anything within two feet of the ground. And you thought deer, gophers and rabbits were a problem?

Sherman is caught red-handed licking the buttermilk/moss mixture from the wall.

I lost my dog Sherman recently but one of my favorite anecdotes about him involved a wall and some buttermilk. The interlocking paver wall at my house in Bonny Doon stood out like a sore thumb and I wanted moss to grow over the concrete blocks like it did on the fieldstone retaining walls. I still remember looking back at the wall after painting on the moss/buttermilk mixture ala Martha Stewart’s instructions and seeing Sherman licking it all off. Even adding hot sauce to the mixture didn’t slow him down but I guess enough moss spores survived as the wall looked pretty good during the wet season before last year. Now I’m not so sure what survived on the wall since the fire but I’ll check on it next winter after the rains start – fingers crossed .

Like everybody else I didn’t go many places in 2020 during Covid times so I fondly remember my trip to Poland years ago. I did a lot of bird watching, hiking and punting. The gardens in eastern Poland were spectacular. The soil there, deposited by glaciers, is rich with sediment and nutrients. Sunflowers border neat plots of cabbage, beets, potatoes, cucumbers, lettuce and leeks. Black-eyed Susan cover the hillsides with swaths of gold blooms. Berries such as currants, blueberry, blackberry and raspberry are grown in large plots and fenced with wire. Every 10 feet or so plastic bags are attached and wave in the breeze. I was told this keeps the wild boar, roe and red deer at bay.
Sure looked funny, though.

This is my 800th column for The Press Banner. The first came about this way. I typed up a sample column and marched into the editor’s office. I’ve forgotten his name but little did I know that he had taken horticulture classes himself and so had a soft spot for my idea to write a weekly gardening column. Next thing I know he says he wants 5 columns, 400 words each, excluding prepositions, on his desk by Friday and the column would be called ‘The Mountain Gardener’ and not ‘Ask Jan’ which I had suggested. I knew my father who always encouraged me to write would be proud. I was now a newspaper columnist.

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