- Author: Jan Rhoades
“You can't grow Canna Lilies here. They are tropical plants, not meant for our zone.” This was a recent statement made by a “dyed in the wool” British gardening friend. If you are an adventuresome gardener, like me, you recognize a challenge when you hear it.
When you go plant shopping at a nursery or garden center, most plants will have a tag that shows the United States Department of Agriculture (USDA) Hardiness Zone. Hardiness Zones were created in order to guide growers and provide gardeners with an easy way to determine which plants are most likely to thrive in any given location. The Zones are defined by the average annual minimum winter temperature. They are then subdivided into sections A and B, based on 5-degree F increments. If you visit the Agriculture Research Service (ARS) (http://planthardiness.ars.usda.gov/PHZMWeb/) web page, it is simple to enter your zip code and find your Zone.
Charlie Mazza, Senior Horticulture Extension Associate at Cornell University, put it best when he said, “In the real world, we garden in microclimates, not hardiness zones.”
A microclimate is the climate of a small area that is different from the area around it. It may be warmer or colder, wetter or drier, or more or less prone to frosts. These areas may be quite small – a protected courtyard next to a building, perhaps, – or it may be quite extensive, an area extending several miles inland from a large body of water, for example. In general, large bodies of water tend to moderate air temperatures of adjacent inland areas - low temperatures in winter are not as extreme, and these areas are less prone to late spring and early fall frosts. Smaller bodies of water, like a pond in your yard, have the same effect, just to a lesser extent.
Another example is urban areas which tend to have less extreme low temperatures that the surrounding countryside because buildings and paved surfaces absorb heat during the day, then radiate it back into the air at night. These buildings also offer protection from the wind.
Topography also has an effect on micro climates. Cold air flows downhill and collects in low spots so hilltops may not suffer as much from frost or cold temperatures. For example, here in Bishop, it is generally colder down at the airport by the Owens River that it is up at Apple Hill Ranch in Wilkerson. Of course, north facing slopes are slow to warm up because they receive less direct sun compared with south facing slopes.
Large scale micro climates dictate how our area is USDA Zoned. There is not much one can do about these effects except to be aware of them and let them guide plant selection and garden timing. However, you can look for smaller scale micro-climate effects at work in your yard and take advantage of them. Just like urban areas, your house absorbs heat during the day and radiates it back at night. It also offers shelter from prevailing winds and presents areas of shade and warmth. Fences, walls and large rocks can provide shelter and radiated heat. Raised beds, terraces and balconies can, like hillsides, offer a warmer, well drained space for growing. Paved surfaces, trees and soil types also offer opportunities and challenges, depending on what you might like to plant.
In addition to the USDA Hardiness Zone, other things that must be taken into consideration when choosing plants include its needs for light, moisture and care throughout the growth cycle. There are also environmental factors such as wind, pollution and localized microclimates.
Be aware of driveways, sidewalks, patios, and paved paths that can absorb heat during the day and re-radiate it at night, moderating night-time temperatures. If impervious, these areas can't absorb water, and may create wet spots if the water that flows off of them goes into one, concentrated area. The same can be applied where water flows out of downspouts and gutters or off of roofs.
Focus, also, on height, spread, and orientation of trees and current plantings. Tall trees can create excellent micro climates on your property by shading and protecting plantings, but they can also prevent rain from reaching the ground and provide too much sun protection in the summer, too little in the winter, especially if deciduous. Another consideration about trees: competition for water and nutrients created by the roots may make it problematic to grow less-competitive plants around the base.
Remember, no hardiness zone map can take the place of what you know and have observed in your own garden and yard. For instance, I made the mistake – some years ago – of planting a sapling cherry tree in what I thought was a fine place – and now I realize that it is in the shade of my large, old apricot tree, so it doesn't get much sun. By the same token, I have learned to plant my lettuce in the shade of other, taller vegetables so that I can have lettuce all summer, right along with my tomatoes!
While we cannot easily arrange and rearrange structures, hard surfaces, and trees on our property, we can incorporate a number of so-called season extenders to add productive days to the normal frost-free growth cycle for your Zone and create microclimates to our advantage:
- Raised beds and containers promote early growth, since they warm up sooner in the spring than the rest of the ground, especially if one edge of the bed or pot faces south. They can also provide optimal soil conditions.
- Use row covers. Woven polyester row covers have the advantage over clear plastic covers because they allow air circulation around the plants. Structures that surround plants...help store heat during the day and release it at night to protect plants from frost.
- Incorporate mulches to create desired micro climates by warming the soil (black plastic), cooling the soil (alfalfa and/or wheat straw), controlling weeds, and conserving moisture.
Let's say you want to have lettuce for your sandwiches and spinach for your salads outside of the “normal” growing season for these vegetables. You can tap into the benefits of creating microclimates in your vegetable garden to accomplish this goal. By utilizing south-facing raised beds in full sun you can get your seeds planted a week or two earlier in the late winter. By planting in containers you can move to a shaded area in the summer, you can extend the productive period for these cool season crops. And, by using winter-weight row covers in the fall, you can protect these tender plants from the falling temperatures...often extending well past the first frost.
Or, maybe you want to grow a canna lily in Zone 7b. Creating a micro-climate by planting in a pot and moving it to favorable locations according to the season is one solution. I chose to put mine in a sunny south facing corner by my house. The corner is protected from the wind and a warm toasty place in any season. I used mulch to keep the roots moist and covered the rhizomes with more mulch to make it through the winter. A raised bed might also be helpful in the future.
Gardening by using the concept of micro climates is, of course, a risk. We shall see what happens if the El Niño winter that is predicted comes to pass. All gardening, in the end, involves risk. And, the more I observe my garden, throughout the day and throughout the seasons, I can see where the microclimates exist, so that at least the risk is calculated!
- Author: Dustin Blakey
What's the dilemma? My kids tell me I have to dress up for Halloween this year, and they won't accept yet another year of me going as a “Farm Advisor” or “a dad.”
My ongoing goal at Halloween has been to have the absolute minimal costume that will allow me to pass muster with the girls, but save what little adult dignity I may have. Each year this gets harder.
I think I've decided on being a mad scientist this Halloween. I already have a lab coat and some safety goggles. (Even mad scientists care about eye protection.) A mad scientist needs a project to work on. Since a nuclear-powered cannon that shoots glowing, radioactive pumpkin pie filling wouldn't do much to help my daughters' chances of scoring a giant cache of candy, I thought I'd come up with some clever alternative to carving pumpkins. After all, nobody likes cleaning up the 20 pounds of pumpkin guts contained within a 10 pound pumpkin. Especially dads who inevitably end up with the job.
The traditional place to start would be vegetables. In the 19th Century, the Scots and Irish used root vegetables common to them. Potatoes (until the Great Potato Famine), rutabagas, and turnips were often carved with scary faces. Going “old school” will probably end up being the least messy alternative, but to be honest, I don't think you will inspire kids with a rutabaga. Especially since they can't easily be made to glow ominously.
One of the better ideas I found was using watermelons instead of pumpkins. This allows you to make green goblins and other creatures. The family can eat the easily carved pink flesh scooped out of the melon which is a nice bonus. Other melons can be carved for even more bizarre creations. I can't stand to eat them, but cantaloupes look like they could be made into some nightmarish monsters.
Plants in the cucumber family like melons and squashes (and pumpkins) generally work well since they have a tough skin and if even their core is not hollow, it is usually soft enough to scoop out. Unusual shaped squashes can lead to inspired designs. A butternut squash turned upside-down looks remarkably skull-like, even if it would be a bit of a chore to hollow. Thankfully there's paint!
If your jack-o-lanterns look like they need some little friends, it's possible to carve large bell peppers into heads, but you won't be able to light it with a candle without it wilting quickly. This leads me to an important observation about lighting jack-o-lanterns.
Pumpkins and winter squash have great flexibility with means to light them. Small tea candles are fine for a flame-based light system, but more creative produce options like melons won't do so well with candles.
If you're clever you can use LED lights to light a jack-o-lantern, but I think glow sticks are the best way to illuminate all your Halloween carving projects. The same large glow sticks you give your kids to wear trick-or-treating are perfect for larger fruit like pumpkins and watermelons. For small items like muskmelons or peppers, use those small bracelet types. You can often find a ten-pack of these inexpensively.
Glow sticks are nice because they stay cool, give you a range of creative colors, don't burn you as you try to set them inside, and won't start fires. With all the ninjas, vampires, ghouls, and zombies out on Halloween, the last thing you need to worry about is open flame.
Instead, be on the lookout for a madman in a lab coat handing out Atomic Fireballs to unsuspecting children.
- Author: Alison Collin
Hellebores, with their neat mounds of evergreen foliage and showy flowers in early spring are hard to beat as plants to cheer up shady spots under trees or on the north side of a house. They are members of the Ranunculaceae family and are generally native to southern and eastern Europe. Clumps of handsome leaves about 12 inches high produce many stems of nodding flowers early in the year. These are rather similar in shape to a cupped wild rose, but close inspection shows that what appears to be petals are in fact sepals. As is often the case where sepals are the showy part of the plant, this has the advantage of giving a prolonged blooming season with the “flowers” staying in good shape for several weeks. The mainly green or white colors of the wild plants have been improved by hybridization and now include a vast array of pinks, slate gray, maroon, spotted and picoteed, but they generally revert to green as they age. Double flowered varieties have also been introduced. Although they are poisonous to humans and animals they all have productive nectaries and are beloved by bees which will visit in large numbers on warm days.
Unlike most shade-loving plants, hellebores prefer a slightly alkaline soil in order to thrive. They do require regular irrigation and a mulch of leaf mold to help retain moisture is beneficial although large clumps can tolerate occasional drying out. The clumps are tightly formed, so they do not invade their surroundings but they resent disturbance once established so a mature plant will often take a couple of years to recover if it is moved (that is, presuming it survives). Likewise it is almost impossible to split a mature clump successfully. However, they frequently seed in large numbers around the parent plant, and it is a simple matter to dig up and transplant the seedlings, but of course the hybrids will not be the same as the parent in color or form.
Hellebores are not touched by deer or rodents, and are renowned for being pest-free; however, in my garden H. orienalis has had a quite serious aphid infestation in just the past two years, perhaps due to the mild winters.
Helleborus orientalis and its hybrids (sometimes described as H.x hybridus) need some winter chill and comfortably grow in Zones 6 and up. They have the widest selection of colors and are probably the most commonly grown and, therefore, most likely to be found in local nurseries. This species is often called the “Lenten rose” (although, of course it is not related to roses) and in my Bishop garden it generally produces a generous crop of 2 inch, white, cupped flowers between March and April. It happily grows as a large clump of dark green leaves on the north side of the house which is mostly in the shade, but between the equinoxes it does get a blast of afternoon sun which sometimes burns the leaves.
Helleborus niger or "Christmas rose" is winter hardy to zone 4 and is lower growing and produces glistening white flowers with yellow stamens in mid-winter. Variety 'Potter's Wheel' has larger flowers than the species and is much sought after, but it is hard to propagate. There are also pink and double flowered varieties. This must have alkaline soil, be protected from strong direct sun, and have a reliably moist soil.
Helleborus argutifolius or Corsican Hellebore grows in Zones 6-9, has coarse, blue-green toothed foliage and clusters of green nodding 2” flowers held on 2ft-3ft long stalks which have a tendency to sprawl. It can become almost shrub-like. Although more sun tolerant, it is not as hardy as the previous two species but has grown under heavy shade on a west-facing wall in Bishop for 6 years without mishap.
Helleborus foetidus or the Stinking Hellebore, is often grown more for its foliage than its flowers. Clusters of small, bright green flowers on long stems arise from clumps of handsome, evergreen foliage. Newer hybrids have been bred to produce interesting foliage such as finely divided leaves or bronze coloring. The plant is hardy to Zone 5, although the flowers will be damaged in those temperatures.
To see a sample of the huge variety of flowers available check out some of the specialist nurseries such as:
- Author: Harold McDonald
Part three of a series on scientific names of plants: Learning Names
Last time we talked about the value of scientific naming in reducing ambiguity and gaining some insight into a plant's characteristics. Like any new language, the best way to learn is to start using it in daily life.
Scientific naming is generally credited to the Swedish scientist Carl Linnaeus with the publication of Systema Naturae in 1735. Binomial nomenclature gives each organism is given a two-word name, the first the genus (which is always capitalized), the second the species name (which is never capitalized, even when derived from a proper name).
Though scientific names are sometimes called Latin names, the names can be drawn from many sources, including Greek and other languages, names of people and places, and sometimes even anagrams—the flowering plant species Muilla is an anagram of the onion genus Allium! Quite often though, the species name can be descriptive. A few of California's many paintbrush species illustrate some of these sources.
- Castilleja angustifolia a paintbrush with narrow leaves
- Castilleja chromosa a very colorful paintbrush
- Castilleja densiflorus a paintbrush with very dense flowers
- Castilleja gleasoni from Mt. Gleason, in L.A. County
- Castilleja lemmoni named for botanist J. G. Lemmon
Next time: start learning the scientific names of plants
- Author: Harold McDonald
Binomial nomenclature is the system of identifying organisms by their Genus species names. The full system of scientific classification, however, involves many broader levels of classification. From the broadest classification, kingdom, you move down through the progressively more restrictive classifications of phylum*, class, order, family, genus and species. A common mnemonic for learning the levels is Kings Play Chess On Fine Grained Sand. A few secondary ranks exist in the plant kingdom, but for most purposes this is good enough.
I think the best way to start learning scientific names is to go up one level from the binomial names, to the families. While there are a lot of families (more than 600!), a small number account for nearly all our common plants. Just two families, the Asteraceae (aster or daisy family) and Fabaceae (pea or legume family) account for more than 42,000 species, and nearly everyone knows what daisies and pea flowers look like. Once you've learned the characteristics of some of the common families—numbers of floral parts, type of symmetry, leaf types, fruit types—it becomes fairly easy for you to identify unfamiliar plants to the family level. Here is a great PDF you can download that illustrates 50 of the most common families. Each family has a gorgeously illustrated page listing the major characteristics of each family, along with prominent plants in each one. (For some reason, if the link won't work type “sdsu 50 plant families” into Google and click on the top hit.)
Fifty is really too many families to try to learn, but if you use that PDF in conjunction with the following link from the website Learn Plants Now, you'll be well on your way to learning about the five biggest families, which account for nearly 60,000 species. By the way, you'll notice there are often two versions of family names given—eg Asteraceae and Compositae for the sunflower family. The ones that end in –aceae are the recognized “modern” names, while the ones that end in –ae are the older ones. Most times you'll see both given, but you might as well learn the new ones.
If you prefer a book, Botany in a Day, by Thomas Elpel is a great choice. The Mono Lake Committee in Lee Vining generally has it in stock.
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* Ed. note: With plants and fungi we usually use "division" instead of phylum. Same meaning, but useful in adding unnecessary confusion. Never was explained to me why we do this. I assume it's tradition. Since 1993 it's been OK to use either. I can't remember the last time I even thought about a plant's division. Family level is more useful.