We have had our first rain, and the nights are starting to get cold. Napans are fortunate: we can enjoy our gardens pretty much year-round and that includes working in them.

I welcome rain. First, it means fire season is over. It also softens the soil, making it easier to pull out weeds.

While I appreciate the relaxed, naturalistic gardening style that is popular today, I still remove weeds. Weeds compete with plants for water and nutrients, and they can take over a yard. They also shelter pests. It's a lot easier to pull them out when the ground is soft. Wear gloves!

I also bought a standing weed puller that I saw at an event at Las Flores Learning Garden in Napa. It is wonderful for a gardener with back or knee issues: we don't have to bend to weed.

Inspect your plants. Remove dead or diseased branches and put them in your yard-waste container. Healthy plant clippings can go in your home compost.

It's still too early to prune roses, but you should dispose of any rose leaves lying on the ground. They may harbor fungus, a common issue with roses.

After you have finished your clipping and trimming, clean, oil and sharpen your tools. Dull tools are tedious to use and hard on plants. Then put the tools away safely.

There is a trend now to leave dried perennials as they are, without cutting them back. After all, that's what happens in nature. Most people have limited space, however, and if you don't want a plant (such as echinacea) to spread, you can deadhead it after the birds enjoy the seeds. A dried milkweed has its own beauty and can add an architectural element to your yard. But you should cut it back eventually to make room for the new growth.

The days are shorter and colder, so adjust your irrigation system. Your plants don't need as much water as they did in the summer. Those of us without irrigation systems are overjoyed that we can cut back on the hand watering.

Renew your mulch. It discourages weeds. Fallen leaves make an excellent mulch and provide habitat for beneficial insects. More food for the birds.

Plant wildflower seeds now for spring and summer bloom. You still have time to plant some bulbs, too.

The biggest danger to plants in winter is frost. Even in Napa, we have had cold snaps with temperatures dipping into the twenties. In my yard, the plants in danger from frost are daphne, brugmansia and Meyer lemon as well as potted pelargoniums, coleus, and lemon verbena.

A plant that has suffered frost damage looks scorched. That's because frost disrupted the plant's water circulation and the plant dried out. You can move small potted plants into a shed, into your house or next to your house, preferably facing south. You can cover them with a sheet but use a frame to keep the sheet from touching the plants to avoid frost damage.

Another option is commercial frost cloth, a lightweight polyester material that can be draped directly on the plant without hurting it. Many nurseries carry frost cloth.

Cloth draping works best for larger plants, like a citrus tree. For smaller plants, prepare for the cold by collecting cardboard boxes. On a night when frost is forecast, just place the boxes over your frost-tender plants. You can also cut the bottoms out of plastic gallon milk bottles and use them as plant protectors.

After it warms up during the day, remove the boxes and sheets. Frost cloth can stay in place because it lets light through. If all this frost protection seems like a lot of labor, consider that it's even more laborious (and sad) to uproot a Meyer lemon tree killed by the cold.

I welcome the “don't work yourself to death” new garden aesthetic, but we can't escape weeding and tidying. We can make the chores more manageable, however. I like to work in 15-minute increments. It is surprising how much you can accomplish in a quarter of an hour. With me, the time usually stretches to 90 minutes without my realizing it.

I get ideas for my yard while I am digging and mulching. I make notes on what was successful that season and what needs rethinking. My dog keeps me company, and I even enjoy watching the squirrels, those little scamps, burying walnuts in a newly tidied flower bed.

Gardening Workshop: Join UC Master Gardeners of Napa County for a free workshop on “Gardening with the Masters” on Saturday, November 18, from 10 am to noon, at Ole Health Garden, 300 Hartle Court, Napa. Children five and older are welcome if accompanied by an adult. Class size is limited. Register to attend.

Help Desk: The Master Gardener Help Desk is available to answer your garden questions on Mondays and Fridays from 10 am until 1 pm at the University of California Cooperative Extension Office, 1710 Soscol Avenue, Suite 4, Napa. Or send your questions to mastergardeners@countyofnapa.org. Include your name, address, phone number and a brief description.

Sources:

Healthy Garden Tips:

   Freeze Protection Simplified

   Garden Checklist Fall

   Using Garden Mulches

The High Line, www.thehighline.org

Every year at this time, deciduous trees drop their leaves. This natural phenomenon has many benefits. For one thing, trees don't really need their leaves now that the days are shorter and there's less sunlight for photosynthesis.

Interestingly, leaf-dropping trees and plants are responding not to the loss of sunlight but to the increasing hours of darkness as the nights get longer. Leaves turn yellow, gold, copper, and orange because the tree is undergoing a phytohormonal process known as abscission. A layer develops between the leaf and the twig it's attached to, cutting off water and nutrients. In a sense, the leaves aren't falling; the trees are pushing them off.

Without their leaves, the trees can put their energy into root and structure growth and strength. They can retain more water and nutrients in these areas during the colder months.

Snow and rain could damage leaves if they remained on the tree. Without leaves, winter's cold air and wind can more easily pass through the branches, minimizing the fungal diseases associated with wet weather. On sunny days, sunlight and warmth can reach the ground under the tree.

If you have deciduous trees shading and cooling your home and yard in summer, you may appreciate the extra light and warmth that you get in winter after those trees lose their leaves.

We can get other important benefits from foliage drop if we let those leaves remain on the ground. First, they provide free organic mulch, better than anything you can buy. The leaves are compatible with the local ecosystem given that they originate here, unlike some storebought mulches made of bark from trees that may not even grow in our area.

Fallen leaves provide a haven for bugs and other microorganisms that appreciate that dark, moist environment. Beneficial spiders, gnats, overwintering butterflies and caterpillars, worms, moths, and bumblebees often take up residence in leaf mulch. Of course, less desirable critters—stink bugs, boxelder bugs, beetles, and roaches—enjoy that leafy habitat as well. We may dislike them, but they play a role in the ecosystem, and we should tolerate them (within reason, of course).

Leave those leaves on your lawn if you still have one. Lawns are no friend to the environment as they provide few nutrients to the local bugs and require too much water and too many chemicals to thrive. However, if you mow any fallen leaves right onto your lawn, they will provide a natural cover and nutrient layer that protects it during the colder and (hopefully) wetter months. Mowing will also reduce the leaf volume and prevent moisture buildup, which can harm a dormant lawn.

Some trees, plants, bushes, and hedges drop so many leaves that they may suffocate the plants under them. Fallen leaves can also harbor fungi or bacteria, and if you leave them near the roots or touching the trunks of a plant, they can promote disease. Better to move the leaves away from the trunk by hand, rake, or broom. You can toss them into your own compost pile or the city's brown compost bins, but don't put them in plastic bags in your garbage. That would be a waste of a beautiful natural resource.

My husband and I have a Raywood ash in our backyard that drops a tremendous number of leaves in the fall. We spread them in our vineyard.

If you want to view this phenomenon, come to the Las Flores Learning Gardens at the Las Flores Community Center in North Napa and you'll see more leaves than you can imagine. They blanket the low-water and native gardens until we can get around to cleaning them up. The leaves are so abundant that we have to order extra compost bins to have them carted away.

 I know, I know. I just said, “don't remove them, move them,” but in this case, we have no place to move them to. At least by sending them to the community compost center, we know they will be properly utilized.

While it's customary to rake and dispose of autumn leaves, I encourage you to give that practice another thought. Leaves can look beautiful and natural in your garden if properly spread. And knowing that you're creating a winter habitat for important species is gratifying. You are doing your part to support the ecosystem.

Lastly, as the leaves decompose, they nourish the very plants that dropped them. Those grateful plants will use the gathered nutrients next spring for the big burst of life that we look forward to after a long winter.

Food Growing Forum:Join UC Master Gardeners of Napa County for a free workshop on “Favorite Food Plants” on Sunday, November 12, from 3 pm to 4 pm via Zoom. Master Gardeners will share the edible plants that they consider to be must-haves in their gardens. Get cultivation and harvest tips, too. Register Here to get the Zoom link.

Gardening Workshop: Join UC Master Gardeners of Napa County for a free workshop on “Gardening with the Masters” on Saturday, November 18, from 10 am to noon, at Ole Health Garden, 300 Hartle Court, Napa. Children five and older are welcome if accompanied by an adult. Class size is limited. Register to attend.

Help Desk: The Master Gardener Help Desk is available to answer your garden questions on Mondays and Fridays from 10 am until 1 pm at the University of California Cooperative Extension Office, 1710 Soscol Avenue, Suite 4, Napa. Or send your questions to mastergardeners@countyofnapa.org. Include your name, address, phone number and a brief description.

Several decades ago, I went hiking on Mount Tamalpais with the mother of a good friend. She handed me a burlap bag—reason unknown—and off we went. I soon found out why she wanted me to carry a bag. She pulled out a terrifying little whip with a knife on the end and, every so often, she would hiss “invasive!” and hand me a hapless sprig she had cut out of the ground.

Mrs. Winston was a stalwart of her local California Native Plant Society chapter, and her mission was to expunge every misbegotten non-native plant from the mountains of Marin. In a short time, the bag was full, and I dragged it down the path, wondering why on earth Mrs. Winston was so upset over a few plants.

I remembered this walk when I decided to write about my English hawthorn tree (Crataegus monogyna), a species in the rose family. The hawthorn towers in my backyard. In the spring it is covered with a veil of white blossoms, and in the winter, it sports red berries that the birds love. It also provides habitat and a hiding place for birds.

I let the leaves of the hawthorn rot on the ground, and they form a layer of decaying vegetation that supports all sorts of insects that birds eat. I have seen birds hide in the leaves when a hawk comes around. While researching my thriving tree, I learned that it, too, is an invasive plant.

According to the University of California, a plant is invasive if it can cause ecological change, spread without human help, grow rapidly, and adapt easily to an environment. Most California invasive plants were introduced by a well-intentioned ornamental horticultural industry or to combat erosion. That's how we got periwinkle (Vinca major), pampas grass (Cordateria selloana), English ivy (Hedera helix), Scotch broom (Cystisus scoparius) and other brooms. 

These plants are scourges in Napa County. Broom was planted for erosion control and is now a pest in Westwood Hill Park. Community members have regular broom-eradication days there. Ivy and periwinkle are attractive, but if they curl around trees, they can cause rot. Ivy is also a favored rat habitat.

Pampas grass was popular in the 1950s—a complement to mid-century modern architecture—but it quickly got out of control. I see it often in Napa. No one recommends it for landscaping anymore.

With 5,000 native plants, California has the greatest natural botanical diversity of any state. About 1,500 non-native plants have also become established here and some are invasive.

Our agricultural economy is enormous, and it can be harmed by invasives. They can change the landscape, compete for nutrients and water, or simply attract wildlife that will harm crops.

Invasives can disrupt natural ecosystems, causing a reduction in wildlife. For example, waterways that are choked with reeds attract fewer songbirds because birds won't nest in the reeds.

If you search for a list of invasive plants online, you will likely recognize several that are in your yard. I have wild allium (onion), ivy, calla lilies and Himalayan blackberry.

Some non-native plants “naturalize,” meaning they spread without human intervention. Some daffodils fall into that category. They don't harm the environment because their spread is limited.

“Noxious” is a legal term in California. It is used to describe invasive plants that are “troublesome, aggressive, intrusive, detrimental or destructive to agriculture, silviculture or important native species and difficult to control or eradicate.” Noxious plants include all manner of thistles, purple loosestrife, giant hogweed, tree of heaven and poison hemlock, among others. (I noticed that noxious plants have unusually vivid names.) Occasionally government agencies will step in to eradicate them.

In my online search for home remediation, I found several sites that advocated glyphosate (Roundup). We don't use that anymore around my house. The best eradication method is to remove the plant by the roots.

In the case of my hawthorn, I can't afford to cut it down. I also like the shade and privacy it gives and the birds it attracts. It's not the worst invasive in the world, I rationalized. The City of Napa planted one 30 years ago in the strip across the street from my house. And I live two blocks from Fuller Park, which is famous for its exotic trees.

I am thinking about preparing myself for my hawthorn's inevitable death by planting a native oak somewhere in the yard. I also will hot-compost any seedlings that appear instead of giving them to a friend as I had promised. She lives in a rural part of the county, not far from valuable vineyards, near the Napa River. English hawthorn does particularly well near waterways.

Do your research before you plant. That is always good advice but especially so with regard to invasives. My calla lilies are confined, I cut back the ivy and blackberries every year, and I am resigned to eating as many wild onions as I can every spring. I planted none of those, by the way.

Last year I met a young man at a Master Gardeners' composting workshop. He was a gardener at the facility where we held the workshop. I admired a tree he was manicuring, and he told me it was a Russian olive tree. I asked him if it needed much care. No, he said, and that was the problem.

Russian olive is an invasive plant that needs little help to thrive. Consequently, he makes sure to dispose of any sprouts.

Years before, as a Cub Scout, he had planted hundreds of these trees in Colorado to stabilize soil near waterways. Years later, descendants of these same trees had invaded the riparian environment, and he spent his college summer vacations pulling thousands of them out of the water.

Food Growing Forum:Join UC Master Gardeners of Napa County for a free workshop on “Favoritie Food Plants” on Sunday, November 12, from 3 pm to 4 pm via Zoom. Master Gardeners will share the edible plants that they consider to be must-haves in their gardens. Get cultivation and harvest tips, too. Register Here to get the Zoom link.

Gardening Workshop: Join UC Master Gardeners of Napa County for a free workshop on “Gardening with the Masters” on Saturday, November 18, from 10 am to noon, at Ole Health Garden, 300 Hartle Court, Napa. Children five and older are welcome if accompanied by an adult. Class size is limited. Register to attend.

Help Desk: The Master Gardener Help Desk is available to answer your garden questions on Mondays and Fridays from 10 am until 1 pm at the University of California Cooperative Extension Office, 1710 Soscol Avenue, Suite 4, Napa. Or send your questions to mastergardeners@countyofnapa.org. Include your name, address, phone number and a brief description

I was lucky enough to buy a small Napa house in 2008. Trees, shrubs, and a lawn dominated the large backyard. Mowing the lawn took a long time due to the rocky terrain and poor shape of the lawn. Not what I wanted to do on a Saturday.

Then there was the weeding and watering. The landscape was not on a drip system and moving the sprinklers around was a chore. Remembering to turn off them was another one. Waking up to find a waterlogged lawn after forgetting to turn the sprinklers off was disheartening.

Then I heard about Napa's Cash for Grass program. The city pays residential water customers up to $750, or a dollar per square foot, to replace existing lawns with low-water-use plants and permeable hardscape and to install drip irrigation—all of which saves time, water, and the environment. That sounded like a winner to me.

The process was easy. I called the city water department and scheduled a pre-inspection appointment with the specialist. After an inspector came out and measured my lawn area, I received a letter approving me for the maximum amount of $750, to be paid when the project was completed within the four-month timeline.

That was the easy part. I had been busy thinking about all the benefits of saving water, time and work while enjoying a beautiful yard, but I hadn't thought about the details. I hadn't considered how to take out the existing lawn, or how much effort and expense that would entail. The devil is in the details as they say.

After researching, I opted to eradicate the lawn with a process known as sheet mulching or cardboard mulching. Some refer to it as lasagna mulching because it requires making layers of cardboard and organic materials. I chose this method because it was inexpensive and had many benefits. The cardboard kills the grass while feeding the soil with organic matter, smothering weeds, and trapping moisture. What could be better?

Sheet mulching involves layering cardboard over closely cut and watered grass, overlapping the cardboard by at least six inches to keep out aggressive weeds and sunlight. You wet the cardboard thoroughly, then cover it with a layer of compost and leaves. Earthworms like cardboard and come up to feed on it, improving the soil in the process.

I soon identified the stores with the biggest cardboard boxes, found out their delivery days and made several trips to load up my small station wagon. After removing any tape and staples, I layered the cardboard over my back lawn. As you might imagine, this process took several weeks.

Once I finished laying the cardboard, I ordered a mound of compost from Napa Recycling & Waste Services and had it delivered to my driveway. A kind neighbor helped me cover the cardboard with two inches of compost, one wheelbarrow load at a time.

For the first few days, the compost was covered with small flies and emitted a deep earthy smell. Thankfully, both the flies and the odor went away.

Next came the drip system. I hired a company to install regulators and lay irrigation lines. Smaller drip lines would be added once the plants were planted.

Looking out over my large compost-covered yard frightened me. I felt like I had artist block. How do I design my yard?

I had ideas from garden tours, Native Plant Society sales, garden magazines and books, but I was unclear how to put my ideas into a cohesive design. I decided to hire a landscape designer to consult on a plan and in the end it was worth it. We discussed my goals, budget, plants, and the types of gardens that inspired me. She came up with a plan for me that I could implement on my own.

Since I did not have to have my yard completely landscaped within four months, I could work on the plan over time. I planted three bare-root trees, an olive tree, a lemon tree, and a few drought-tolerant plants to start. I had an area dug out for a sunken “secret garden” in a back corner, and placed steppingstones around the yard.

My son and his fiancée built three raised beds for vegetables, and I planted a small herb garden. By the end of the fourth month, 50 percent of the former lawn area had been planted and it was time to call the inspector.

I am definitely saving water, but I probably spend more time in my garden now than I spent mowing the lawn. The difference is that now I enjoy being in my garden.

That experience was 14 years ago. Napa still offers the Cash for Grass program, but now they have added the Flip Your Strip program. You can earn two dollars per square foot to convert your parking strip, the area between your sidewalk and street. You can also receive a discount on an easy-to-install sprinkler controller that provides self-adjusting schedules. Yout customize your yard-watering needs, determining exactly where and when to water.

You can also get a rebate on a smart home-water monitor that helps detect leaks and reduce your water bills. Call your local water department for specific details and offers in your area.

Library Talk: Join UC Master Gardeners of Napa County and Napa Library for a free talk on “Finding Our Place in Nature's Community Through Books” on Thursday, November 2, from 7 pm to 8 pm via Zoom. We'll share books that inspire us to learn about other species, work toward balance with nature, and live in harmony with nature. Register Here to receive the Zoom link.

Food Growing Forum:Join UC Master Gardeners of Napa County for a free workshop on “Favoritie Food Plants” on Sunday, November 12, from 3 pm to 4 pm via Zoom. Master Gardeners will share the edible plants that they consider to be must-haves in their gardens. Get cultivation and harvest tips, too. Register Here to get the Zoom link.

Help Desk: The Master Gardener Help Desk is available to answer your garden questions on Mondays and Fridays from 10 am until 1 pm at the University of California Cooperative Extension Office, 1710 Soscol Avenue, Suite 4, Napa. Or send your questions to mastergardeners@countyofnapa.org. Include your name, address, phone number and a brief description