Indoor garden plants are completely dependent on the gardener for their moisture needs. (Hopefully no rain falls inside the home!) When to water, how to water and what kind of water to use are key considerations to keep plants in top-notch health.

I love to care for my indoor garden plants and most mornings find me making the rounds to check soil moisture levels. Even indoors, watering needs are quite dependent on weather and the seasons. During a period of cloudy, damp weather, plants will need far less water than if the sun was shining. Soil can dry out more quickly during the heating season.

Two simple rules.
1. Know the watering requirements of each plant. Ferns, bulbs and many indoor flowering plants such as African violets, cyclamens, gloxinias and mums prefer evenly moist soil. Many grown as foliage plants including ficus, ivies, philodendrons, spider plants and tradescantia like the top inch of soil to dry out between waterings. Cacti and succulents generally need much less water.
2. Drainage is crucial for indoor garden plants. All my plants are in pots with holes in the bottom. I adore beautiful containers and usually have a pot-within-a-pot. To water, I remove the inside pot, bring to the sink, water, let drain and then return to the pretty pot.

Three simple steps.
1. Water only when necessary. Since you know the plant's moisture requirements (See #1 above.), look at the soil and stick a finger down into the pot.
2. Water the soil (not the foliage) until about 10% of the total water drains out the bottom of the pot. You'll ensure that the entire root ball was watered and, in addition, you'll have leached any excess salts and fertilizers.
3. Don't allow the pot to sit in water. If the plant is too heavy or cumbersome to take to a sink, water in place and allow the excess to collect in a saucer. Then–and this is important–empty the saucer. Otherwise, the water will be re-absorbed and soil will become water-logged. (Remember the soil science lesson? Soil needs air pockets of about 50%.)

What kind of water?
The best water is room-temperature, untreated water. If your hot water is softened, use water from the cold faucet and let warm to room temperature before use. If your water contains fluoride or chlorine, fill the watering can and let rest for 24 hours. The chemicals will escape as gas.

During summer, water collected from a rain barrel is ideal.

Photo above: Trio of watering cans--full of water and ready for action.

Lest you think I don't follow my own advice, "When at greenhouses, nurseries or any place that sells gardening supplies, check out the clearance areas. Maybe there's last year's model…", I present the following tale as evidence.

My husband, Jerry, and I have been spending some time near Tulsa, Oklahoma. Part of the enjoyment of travel for me is to explore and to discover. I sniff out coffee shops, book stores and places to buy good bread.

Also, I'm always on the prowl for flower shops, greenhouses and nurseries. Imagine my excitement and anticipation last week as I sped down an Oklahoma highway on my way to Tulsa's nicest nursery.

The place positively bustled with green-smocked workers. Some were inside planting and watering and setting up displays. Outside, others moved pallets and unwrapped winter-protected evergreens.

I wandered around for perhaps an hour or so–a few items were piled in my cart–when I spotted a huge, gorgeous glazed pot in a sumptuous shade of turquoise in a corner of a back greenhouse. It was clearly last year's pot as it was planted with an overgrown geranium with bright chartreuse foliage and a pink-blooming dipladenia. The whole thing was stunning. And it was marked down 50%. And I wanted it.

After a brief struggle with logistics–I was 750 miles from my home in Minnesota and we were staying in a rental home and the thing was big and heavy–I bought it.

Once home, my turquoise container will be an arresting point of emphasis for my indoor garden. Later in May, we'll move it outside where it will highlight the deck.

This also appeared in the Askov American, Askov, Minnesota.

Soil Science isn't the most scintillating of subjects (and the nerd ratio can be quite high) but basic knowledge of and understanding about soil is essential whether a gardener, horticulturist, naturalist, landscape designer, botanist or forester.

Soil facts.
To save time and alleviate boredom, I've collected some bullet points.
• Soil is the mineral and organic matter on the top layer of the earth's surface suitable for the growth of land plants.
• Soil is formed by environmental factors (water and temperature) and by organisms acting on parent rock material over time.
• Soil is not the material on the earth's surface areas that are permanently covered by more than 8 feet of water.
• Plants need soil as a water and nutrient source. Tiny tertiary roots are the major absorption means.
• Most plants need soil as the means of support. Exceptions include epiphytes which grow in trees and have aerial roots that don't reach the ground.
• Productive soil is about 50% air that alternately fills with water for use by the plant and then slowly dries out.
• A fascinating, vital, complex symbiosis occurs between soil and soil organisms. And, according to Horticulture magazine, "There are more living organisms [in one handful of soil] than there are people in the world."
• Healthy soil = healthy plants.

Soil for indoor gardens.
The best source for indoor garden soil is a bag of top-notch potting soil from your favorite greenhouse or nursery.

Potting soil is usually an assortment of organic materials in various amounts: peat moss, perlite, vermiculite, compost, sand and lime. Potting soil for cacti and succulents should have more sand while orchids and bromeliads need a mixture of mostly chopped bark.

Read the label carefully on the bag of potting soil. Don't buy "garden soil" or "topsoil."
Also, don't use soil from the outdoor garden where the soil is many feet deep and water can drain well away from plant roots.

If you're a do-it-yourselfer or have a large indoor garden, consider making your own. It's a little like cooking–assemble the ingredients, add the right amounts of each and mix. Plus, I love the feel and smell of the soil. Information on creating potting soil mixtures is in the entry below, Mix your own potting soil.

Take care of your soil.
Just as in gardening outdoors, take care of your soil.

Always provide drainage. In my opinion, water-logged soil, which we now know doesn't have any air pockets, is the prime killer of indoor garden plants. Water should be able to flow out the bottom of the pot and, further, the pot should never be allowed to sit in water.

In addition, organic components such as peat moss and compost break down and nutrients get used up over time. Soil then compacts and shrinks which reduces that nice ratio of 50% air. When that happens, do one of two things.

#1. Top-dress. Gently scratch away the surface soil and replace with 1" of fresh compost.
#2. Repot. Periodic re-potting is necessary even if the plant isn't pot-bound.

Finally…
You could pass Soil Science 101 now but here's one last tidbit. Plants grow in soil. Soil is not dirt. According to my dictionary, dirt is "a filthy or soiling substance, such as mud, dust, or excrement."

*** This column used information from the Soil Science Society of America (wouldn't they be fun to party with?) and the books Soil Taxonomy, Wyman's Gardening Encyclopedia and The American Heritage Dictionary of the English Language.

Photo above: This healthy indoor garden uses a metal window box and contains clubmoss (Selaginella kraussiana), geranium (Pelargonium 'Black Velvet Rose') and English ivy (Hedera helix). All three plants are in individual pots with drainage holes. I check each daily and when one needs watering, I simply take it out of the window box and bring it to the sink where I water thoroughly until about 10% has drained out the bottom of the pot. I then slip the plant back into the window box.

This also appeared in the Askov American, Askov, Minnesota.

It's easy and fun to mix up a big batch of potting soil. Plus, it's cheaper than buying pre-mixed bags.

These recipes are from a book by Alice and Brian McGowan, Bulbs in the Basement Geraniums on the Windowsill. With perhaps the exception of Turface, all ingredients should be readily available at nurseries and garden centers.

The McGowans wrote that Turface "consists of calcined clay, which is clay that has been heated, in a process similar to the firing of clay pots, until the moisture is removed. In their texture, the small angular bits of baked clay resemble kitty litter; the color is of terra-cotta pots." Further, Turface prevents soil compaction and has a unique ability to hold moisture.

The dash of lime is necessary to counteract the acidity of peat moss.

All-purpose mix
1 part peat moss
1 part sand
1/4 part Turface
1/4 part compost
dash of lime

Succulent mix
3/4 part peat moss
1 part sand
1/2 part Turface
1/8 part compost
dash of lime

Tropical mix
1 part peat moss
3/4 part sand
1/4 part Turface
1/2 part compost
dash of lime

My #1 rule for gardening outdoors is simple but powerful: put the right plant in the right spot.

My #1 rule for indoor gardening is the same. Plant location is paramount and, further, light is the most crucial need to supply.

Plants need light.
Why is light essential to plant health?

Because we humans run on food, we tend to think that plants depend on fertilizer (as "food") in a very fundamental way. Certainly they do, but plants derive most of their energy from light.
~ Barbara Pleasant, The Complete Houseplant Survival Manual

In the presence of the complex, green pigment called chlorophyll, plants have the awesome and unique ability to carry out the process of photosynthesis. In the presence of sunlight, plants transform carbon dioxide and water into oxygen and sugar. This sugar is their source of food and energy.

If a plant doesn't receive enough light for adequate photosynthesis, it starves to death.

Assess light levels.
Since, of course, you want healthy plants, let's evaluate light in the home. Address the following questions and understand their consequences should provide essential information. (Although artificial lighting is an option, most people depend on natural light from windows.)

• Which direction do windows face: east, west, south or north? East light in summer and winter (although weaker) is excellent as it is bright but never hot. West light in summer is harsh and scorching while in winter is fine light. Due to the extreme declination of the winter sun at our northern latitude, light from a south window is fairly weak while from that same window will be intense in summer. North windows in the winter provide almost no light but in summer offer enough light for many plants.
• Is light blocked by awnings, roof overhangs or a covered porch?
• Do trees block windows? Conifers could severely limit available light but deciduous trees will be bare during the peak indoor gardening season.
• What color are the interior walls? Pleasant wrote: "In rooms with dark walls, good plant-growing space is limited to 12-24 in. from the windowpane, while rooms with light-colored walls can accommodate large plants, or plants placed more than 24 in. from the window."

What if the assessment shows that the best light in your home is under the big window in the living room where the couch is placed? Easy. Move the couch. Ditto for the awnings. Remove them.

Finally…
In indoor gardening, portability should be a key consideration. I have trays in different sizes and styles that can be loaded up with plants and placed on different tables depending on the season.

Think also about portable furniture, such as shelves and plant stands, that can be moved easily from window to window and from inside to outside. About 30 years ago I bought a stainless steel wire Metro shelf that has been everywhere with me. Many, many plants have been grown on those shelves–and in various living rooms, kitchens, garden rooms and porches.

This also appeared in the Askov American, Askov, Minnesota.

Today continues the series I introduced on January 11, 2010, when I proposed a paradigm shift vis-?É -vis gardeners and winter–the Indoor Garden. This new notion takes aspects of outdoor gardening and moves them inside.

This will be fun. Let's begin.

Just living isn't enough, said the butterfly. One must also have sunshine, freedom and a little flower.
~ Hans Christian Andersen

Careful readers know that, in my opinion, containers that hold plants are vitally important for the health of the plants and for aesthetic reasons. In the past my emphasis has been on containers for outdoor use but when viewed now through the eyes of an Indoor Gardener, the same theory applies.

Basically, put a $5 plant in a $50 container. In the short term, the look is far more pleasing and, in the long term, the container is a sound investment. It will hold countless plants over many years and will become a valuable piece in the collection of pots.

For collection is how I view it. Start gathering pots. You'll need to be prepared to have a proper Indoor Garden. Who knows what plants might be brought home from the grocery store and the greenhouse? Who can anticipate what coleus or fuchsia or begonia might be overwintered inside?

Consider all kinds of containers: antique urns, moss-encrusted olive jars, quirky pots, sleek and sophisticated pots, wicker baskets. Consider different materials: terra cotta, stone, metal, wood and concrete. Look for different sizes, too.

Where to find containers for your collection?
• Look in the shed where summer gardening things are stored. No doubt there are treasures never before considered. Clean them up and haul them inside. I'm pretty certain the pots aren't labeled "For outside use only."
• When at greenhouses, nurseries or any place that sells gardening supplies, check out the clearance areas. Maybe there's last year's model (who cares?) or one with a slight chip (adds character) or one that everyone else thought was weird but you find delightful.
• Cruise art shows, craft fairs, flea markets and antique shops.

Options are everywhere. The sky is the limit. Have fun.

This also appeared in the Askov American, Askov, Minnesota.

In northern climates, there are many months when it's impossible to garden outside. How do gardeners cope? What do they do?

Many gardeners exhale mightily at the end of the outdoor season and are perfectly content to store watering cans and trowels until spring.

Others, perhaps, ignore the frozen landscape outside and instead indulge in a fanciful world of possibilities. For in January, catalogues from mail-order nurseries begin filling the mailbox.

For gardeners, this is the season of lists and callow hopefulness; hundreds of thousands of bewitched readers are poring over their catalogues, making lists for their seed and plant orders, and dreaming their dreams.
~ Katherine S. White, Onward and Upward in the Garden

In addition to studying catalogues, gardeners can work through a stack of beguiling books.

I'm quite certain that Tasha spends every winter evening huddled close to the toasty fireplace with her reading spectacles perched on the edge of her nose, poring over every seed catalogue and gardening book she can lay hands on.
~ Tovah Martin, Tasha Tudor's Garden

Some gardeners have inclinations similar to the wonderfully cranky Henry Mitchell, a former columnist for The Washington Post.

The days are now at their shortest and the gardener should keep it in mind that his ill-humor and (as it may be) gloominess is directly linked to the nadir of the year…Whenever there are ice storms, pull the window shades down.
~ Henry Mitchell, The Essential Earthman

Joe Eck and Wayne Winterrowd are serious gardeners who have built an extremely successful, nationally renowned business around their five-acre, Vermont garden–but even they complain.

January is, quite simply, the year's low point for gardeners. For though one may take brisk walks, weather permitting, or hit the ski slopes, or the treadmill in the bedroom, though there may be a fragrant fire of birch logs on the hearth or a savory pot on the back of the stove…still, January is, as far as gardening goes, not a whole lot of fun.
~ Joe Eck and Wayne Winterrowd, A Year at North Hill

All are fine ways for a gardener to pass time in winter. I have another idea. With a subtle shift in focus, let me introduce an entirely new coping mechanism.

The Indoor Garden.

My notion of the Indoor Garden examines indoor spaces with the same critical eye as outside spaces. It takes into account architectural features and interior design styles of the house. It examines the amount of light available, whether natural or artificial. It borrows aspects of outdoor gardening and applies them inside including the use of container gardens, window boxes and hanging baskets of mixed plants. It tackles cultural needs of plants. Further, it incorporates design principles and elements which ensure that the Indoor Garden is a visual success.

Finally, and this is the best part for a gardener, the Indoor Garden banishes the notion of "houseplants" and opens the floodgates to new plant possibilities–everything from bulbs to tropicals to tender perennials.

Not all aspects of gardening outdoors are possible, of course, in an Indoor Garden. There can be no shrub border of azaleas and hydrangeas and, alas, no room for a perennial border or a vegetable garden. But there could be space for woody plants in containers, impressive hanging baskets and a tiny kitchen garden of sturdy herbs.

In future entries I'll explore this new approach and, hopefully, move winter from the "nadir of the year" to a season of lush green growth, fragrant flowers and beauty.

This also appears in the Askov American, Askov, Minnesota.

Here's a simple, cool idea--and one that shouldn't alarm husbands who might be wary of indoor window boxes--a tabletop garden.

From the snowy garden outside, I hauled in a nifty table and cleaned it up. I placed a large metal tray on top of the table, put the table in a good spot in front of a window and then grouped an artful assortment of plants on the tray.

The plants have changed over the weeks because the oregano, English ivies, some cyclamen and a distinctive, fuzzy succulent were given as gifts. Currently, though, I'm growing, among other plants, a tiny lemon cypress tree, a very fragrant lavender, more cyclamen (didn't give them all away!) and a rose-scented geranium started as a cutting from my friend, Josette.

A fun–and compulsory–part of this project is to change the display often to keep it fresh…and seasonal. I'll add potted bulbs like crocus, hyacinths and daffodils and perhaps more herbs. I'll move or toss any that become bedraggled. Finally, I'll always save room for just one more, simply irresistible plant.

Since gardens outside are entering their period of dormancy and all is faded to muted shades of tan and brown, let's bring the garden concept inside and enhance indoor spaces. In the deep, dark days of winter, we all need to see, smell and luxuriate in lush green growth and some raucous flowers.

What about an indoor window box?

Take the concept of that windowsill herb garden in the kitchen one step further. Choose a window box that matches, blends or provides a nifty foil to your current style and install at sill level.

Don't plant directly into the window box. When plants are kept in their original pots maintenance is a breeze. Add excelsior or moss to the top to make it all look pretty.

Keep the window box fresh. As plants fade simply swap them out for new ones. Change the design with the seasons–fill with poinsettias at Christmas, cyclamen in January and pots of flowering bulbs in the spring. For additional design ideas, refer to my Column entry on September 13, 2007.

Enjoy!

P.S. My husband thinks this is a dumb idea. "Why attach a very heavy, probably dirty, wet thing to an inside wall or window sill?" Well, we all have different opinions! Maybe it was a bit over the top but I still think the basic concept was good.