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Don't let your plants go hungry
By Kathy LaLiberte
According to the Gallup Gardening Survey, less than half of the country's home gardeners use any kind of fertilizer on their lawns or gardens. What's unfortunate about this statistic is that it means gardeners aren't getting as many flowers or as much produce as they should. And they're probably struggling with disease and insect problems that could be avoided. Well-fed plants are healthier, more productive and more beautiful. This article covers the basics of why and how to fertilize your garden.
Plant Nutrients 101
Plants need to be fertilized because most soil does not provide the essential nutrients required for optimum growth. Even if you are lucky enough to start with great garden soil, as your plants grow, they absorb nutrients and leave the soil less fertile. Remember those tasty tomatoes and beautiful roses you grew last year? It took nutrients from the soil to build those plant tissues. By fertilizing your garden, you replenish lost nutrients and ensure that this year's plants have the food they need to flourish.
There are six primary nutrients that plants require. Plants get the first three—carbon, hydrogen and oxygen—from air and water. The other three are nitrogen, phosphorus and potassium.
Nitrogen helps plants make the proteins they need to produce new tissues. In nature, nitrogen is often in short supply so plants have evolved to take up as much nitrogen as possible, even if it means not taking up other necessary elements. If too much nitrogen is available, the plant may grow abundant foliage but not produce fruit or flowers. Growth may actually be stunted because the plant isn't absorbing enough of the other elements it needs.
Phosphorous stimulates root growth, helps the plant set buds and flowers, improves vitality and increases seed size. It does this by helping transfer energy from one part of the plant to another. To absorb phosphorous, most plants require a soil pH of 6.5 to 6.8. Organic matter and the activity of soil organisms also increase the availability of phosphorus.
Take your garden from good to great with the right fertilizer.
- Vegetable Fertilizers
- Flower Fertilizers
Potassium improves overall vigor of the plant. It helps the plants make carbohydrates and provides disease resistance. It also helps regulate metabolic activities.
There are three additional nutrients that plants need, but in much smaller amounts:
- Calcium is used by plants in cell membranes, at their growing points and to neutralize toxic materials. In addition, calcium improves soil structure and helps bind organic and inorganic particles together.
- Magnesium is the only metallic component of chlorophyll. Without it, plants can't process sunlight.
- Sulfur is a component of many proteins.
Finally, there are eight elements that plants need in tiny amounts. These are called micronutrients and include boron, copper and iron. Healthy soil that is high in organic matter usually contains adequate amounts of each of these micronutrients.
Organic vs. Synthetic
Do plants really care where they get their nutrients? Yes, because organic and synthetic fertilizers provide nutrients in different ways. Organic fertilizers are made from naturally occurring mineral deposits and organic material, such as bone or plant meal or composted manure. Synthetic fertilizers are made by chemically processing raw materials.
In general, the nutrients in organic fertilizers are not water-soluble and are released to the plants slowly over a period of months or even years. For this reason, organic fertilizers are best applied in the fall so the nutrients will be available in the spring. These organic fertilizers stimulate beneficial soil microorganisms and improve the structure of the soil. Soil microbes play an important role in converting organic fertilizers into soluble nutrients that can be absorbed by your plants. In most cases, organic fertilizers and compost will provide all the secondary and micronutrients your plants need.
Synthetic fertilizers are water-soluble and can be taken up by the plant almost immediately. In fact applying too much synthetic fertilizer can "burn" foliage and damage your plants. Synthetic fertilizers give plants a quick boost but do little to improve soil texture, stimulate soil life, or improve your soil's long-term fertility. Because synthetic fertilizers are highly water-soluble, they can also leach out into streams and ponds. Synthetic fertilizers do have some advantages in early spring. Because they are water-soluble, they are available to plants even when the soil is still cold and soil microbes are inactive. For this reason, some organically-based fertilizers, such as PHC All-Purpose Fertilizer, also contain small amounts of synthetic fertilizers to ensure the availability of nutrients.
For the long-term health of your garden, feeding your plants by building the soil with organic fertilizers and compost is best. This will give you soil that is rich in organic matter and teeming with microbial life.
Plants can absorb nutrients eight to 20 times more efficiently through their leaf surfaces than through their roots. As a result, spraying foliage with liquid nutrients can produce remarkable yields. For best results, spray plants during their critical growth stages such as transplanting time, blooming time and just after fruit sets.
What About pH?
Even if proper nutrients are present in the soil, some nutrients cannot be absorbed by plants if the soil pH is too high or too low. For most plants, soil pH should be between 6.0 and 7.0. A soil test will measure the pH of your soil. You can send a sample to a lab (contact your local extension service for a low-cost kit) or buy a home kit and do it yourself. Lime or wood ash can be used to raise pH; sulfur or aluminum sulfate can lower pH. Keep in mind that it's best to raise or lower soil pH slowly over the course of a year or two. Dramatic adjustments can result in the opposite extreme, which may be worse than what you started with. Once again, a helpful solution is to apply compost. Compost moderates soil pH and is one of the best ways to maintain the 6.5 ideal.
Our slow-release, granular GSC Organic Tomato Fertilizer (5-6-5) gives your tomatoes all the nutrients they need, including plenty of phosphorus for big, abundant fruit. For a healthy start, mix a handful into the soil at transplant time and then side dress when tomatoes begin to set fruit. Also ideal for peppers and eggplant.
How to Choose a Fertilizer
In most cases, an all-purpose, 5-5-5 fertilizer will provide the nutrients all plants need for healthy growth. If a soil test reveals certain nutrient deficiencies, or if you want to tailor your fertilizer to the needs of particular plants (tomatoes vs. flowers), you can select a special formulation. What you choose will depend on your soil and what you are growing. The three numbers that you see on a fertilizer label, such as 5-5-5, tell you what proportion of each macronutrient the fertilizer contains. The first number is always nitrogen (N), the second is phosphorus (P) and the third is potassium (K). This "N-P-K" ratio reflects the available nutrients —by weight—contained in that fertilizer. For example, if a 100-pound bag of fertilizer has an N-P-K ratio of 5-7-4, it contains 5 pounds of nitrate, 7 pounds of phosphate (which contains phosphorous), 4 pounds of potash (which contains potassium) and 84 pounds of filler.
Note that the N-P-K ratio of organic fertilizers is typically lower than that of a synthetic fertilizer. This is because by law, the ratio can only express nutrients that are immediately available. Most organic fertilizers contain slow-release nutrients that will become available over time. They also contain many trace elements that might not be supplied by synthetic fertilizers.
Fertilizers offered by Gardener's Supply are either all-organic, or contain primarily organic materials. To build the long-term health and fertility of your soil, we recommend using granular organic fertilizers. Supplementing with a water-soluble fertilizer ensures that your plants have the nutrients they need when they're in active growth.
Using Perlite in Your Garden
Born from volcanic glass, baked in a high-temperature oven, and available at your local garden superstore, perlite is one of nature’s most efficient and functional soil amendments. The thing about fads though, they come and go; so, the real question is, should you buy into the perlite revolution?
In a word? Yes.
Perfect soil for your garden would drain well, filter efficiently, be free of diseases and insects, insulate roots, deliver nutrients to roots, be inexpensive, avoid compacting…we could continue, but you get the idea. Why is this relevant? Because perlite helps your soil to do all of those things.
Perlite is a volcanic glass that is ultra lightweight and mined a significant amount in the United States. When heated over 1500 degrees Fahrenheit, the little glassy mineral expands as much as 20 times its original size due to water trapped inside trying to evaporate. This is the property that makes perlite such a unique mineral and so great for gardening.
When mixed with soil, perlite keeps soil aerated. Its low density and pockets of air keep soil from compacting very tightly around it, and as a result, roots can easily reach deeply into perlite. This aerated soil drains water effectively too. In addition to soil aeration, perlite holds moisture excellently, but does not become soggy like most soils and additives. Its unique air qualities also balance soil temperature and insulate roots against rapid temperature changes.
What else makes perlite great? Well, conveniently, it’s toxin-free and therefore safe for plants. Most other soil additives bring with them the risk of disease to plants as well as unique insects and weeds. Perlite is a sterile mineral (due in large part to the high-temperature expansion process) and also has a neutral pH.
Of course, to cap off the great mineral’s traits, perlite is also rather inexpensive. Just thought you’d like to know.
Expert gardeners have been using perlite for years to improve the quality of their garden soil. Plants grow strong roots quickly in perlite and receive enhanced protection from disease, temperature changes, and drowning while bedded in the magic mineral. Of course, there are guidelines to effective perlite use, so before you pour it on too thickly, here’s a guideline or two: Though most plants will grow in pure perlite, the most effective use of the substance is as an additive to your normal garden soil. Garden experts recommend a 50/50 split between normal, loamy soil and perlite. If you’re just looking to give your garden a boost, then try digging down into your garden soil about six inches. Then add about four inches of perlite before covering in your normal soil again. This layer of perlite at the root level of plants will give benefits to your garden produce where it counts–at the roots. Remember, perlite is inorganic which means it will not decompose. This is great news for today’s gardener because the perlite you put into your garden beds will stay there for years to come. So before planting next year, consider adding perlite to your list of preparations and enjoy the benefits of this volcanic glass every season!
Top Crops for Small Vegetable Gardens
What to grow when you have small spaces for gardening
By Ellen Ecker Ogden
Growing a small vegetable garden is like living in a small house: It's not as easy as it looks. One of the keys to success is making good plant choices. Choose compact, productive plants that take up less space yet still provide plenty to harvest.
I learned this when I moved from a 10-acre farm to a small city plot. I had to rethink my vegetable garden. No longer could I grow anything that piqued my interest. I had to become much more selective.
Every year, seed catalogs feature an expanding selection of vegetables, including many that are chosen specifically for their compact nature. While many gardeners value productivity and flavor, small-space gardeners also look for plants that have ornamental qualities and longevity.
It took a few years of whittling down my list to come up with the crops I grow every year in my small garden plot. I start wtih a foundation of tried-and-true favorites: lettuce, basil, and tomatoes. Yet I leave space to try a few new varieties each year. To supplement my harvest, I buy vegetables from a CSA or farmers market. Below are a few of my recommendations, along with those from seed companies that conduct extensive trials to deliver the best varieties.
Every gardener plants sweet basil, and for good reason. The tiny aromatic leaves awaken the senses, adding bright flavor to pesto, salad dressings and more. There are more than 80 varieties of basil, including a few "miniature" types that are perfect for small-scale gardens. A variety called Pistou is the most diminutive form of sweet basil, ideal for planters or windowboxes. The tight green mounds can be used for edging in a larger planter.
Basil is easy to grow from seed, and available from most seed catalogs. More: Learn how grow basil in the Vegetable Encyclopedia.
Pistou Basil. Photo: Urban Farmer
"Cut-and-come-again" is a welcome quality in any garden plant. Harvesting leaves actually encourages more growth. Combine this with its upright growth habit and brightly colored stems,Rainbow Chard works well in tight spaces. Johnny's Seeds offers Bright Lights, which has stems in pink, yellow and ruby red. Because chard is in the beet family, it is easy to grow from seed, but note that the seedlings will need to be thinned to ensure proper spacing. For small containers, it is easier to start with transplants instead of seeds — no thinning required. More: Learn how grow chard in the Vegetable Encyclopedia.
Brightly colored chard shares a windowbox with osteospermum daisies.
Oriental eggplants are known for their compact habit, making them a good choice for pots and planters. Choosing a favorite among the dozens of varieties is difficult. GwenaelEngelskirchen, trials manager at High Mowing Organic Seeds, says Ping Tung Long earns a spot at the top of her list. "Slender purple eggplants hang from compact plants of this lovely heirloom variety, " she says. "The plant stays small but has the potential of producing a lot of eggplants." Because the 10"-long fruit is narrow, it's ideal for slicing and cubing; skin is tender and the flavor is mild. Sow seeds indoors and transplant to pots and planters when warm weather arrives. Tip: When starting seed for eggplants and peppers, use bottom heat for better germination. Place seedling trays on agerminating mat set at 85 degrees F., or on top of the refrigerator, where the heat from the appliance will provide warmth. More: Learn how grow eggplants in the Vegetable Encyclopedia.
Ping Tung Long eggplant. Photo: High Mowing Organic Seeds
Hot peppers are the ultimate ornamental edible for windowboxes and compact gardens. The plants are ornamental and the fruit is long-lasting. "It's hard to pick a favorite," says Nina Burokas of Sustainable Seed Company, who admits that she is crazy about all hot peppers. "Black Hungarian pepper is so colorful that it not only belongs in the garden, but on the patio in pots as well." Purple flowers highlight the emerald-green foliage. During the season, the fruit turns green, then black and finally red. The plants can grow to about 30-36", which makes them a little big for a windowbox, but fine for larger containers. For smaller plants, try their Patio Fire pepper seeds. The narrow fruit grows upward, resembling flames. Color goes from yellow to orange and matures red. Sow seeds indoors and transplant to pots and planters when warm weather arrives. More: Learn how grow hot peppers in the Vegetable Encyclopedia.
Black Hungarian pepper. Photo: Sustainable Seed Company
Fast-growing and prolific, cherry tomatoes can overwhelm a trellis in short order. However, growers have introduced compact varieties that are tame enough for smaller spaces. For instance, Cherry Cascade grows happily in a hanging basket and produces hundreds of tomatoes. The variety is recommended by Susan Romanoff of Gardener's Supply, who grows them in her northern Vermont garden. "Perfect scale! Slightly draping but not so long or heavy that they reach low to the ground," she says. Fruit ranges from the size of a marble up to a golf ball. It has good tomato flavor — not candy-sweet like some cherry tomatoes. Plants are tolerant of drought and the fruit is less prone to the cracking and blossom-end rot, which frequently afflicts the full-sized tomato varieties. Start from seed or find plants in a local nursery. More: Learn how grow cherry tomatoes in the Vegetable Encyclopedia.
A Cherry Cascade tomato, tumbling over the edge of anElevated Raised Bed
The word mesclun means miscellaneous greens, attributed to wild weeds once foraged by peasants in Europe to supplement their limited diets. Many of the mixtures found today are made up of quick-growing arugula and mustards, not ideal for containers. However, you can create your own container-friendly mesclun. Consider Italian endives and escaroles, which can be harvested leaf by leaf. Or, try purslane, which has unusual, succulent leaves that are high in omega 3 fatty acids. Seed companies offer mixes that are suited to the season, so you can start with a spring mix. After harvest, replant with a blend that can withstand summer heat, followed by a third planting of fall greens, such as cold-tolerant kale and collards. Seeds for mesclun is widely available, with an especially good selection at Wild Garden Seed. Here you will find everything from Wrinkled Crinkled Crumpled Cress to Purple Rapa Pop Mix. By the way, Purple Rapa is a cold-season salad mix selected for solid purple leaves, cold hardiness, and disease resistance. "Best color will manifest between the fall and spring equinoxes." More: Learn how grow mesclun in the Vegetable Encyclopedia.
Mesclun growing in our display garden
Lettuce comes in all shapes, sizes and colors, yet the key to a great-looking container garden is to mix it up. Plant different types of lettuce, starting withLittle Gem, a mini romaine that forms a sweet, dense heart. Add some Merlot, a striking red butterhead, and LollaRossa, a loose-leaf type with frilly leaves. Lettuce typically grows from seed to salad in 45 days, plan to harvest them leaf-by-leaf to stretch out season, or have a successive crop ready to fill in the gap.More: Learn how grow greens in the Vegetable Encyclopedia.
LollaRossa lettuce. Photo: High Mowing Organic Seeds
A natural choice for containers and small-space gardens, edible flowers add unmistakable charm. My favorites include nasturtiums, violas, and calendula, which can be planted early in the season and will continue all summer long if kept picked. The signet marigold,Lemon Gem, is a mainstay in my garden because of the aromatic ferny foliage that releases a lemon scent. If you don't find transplants, most edible flowers are easy to grow from seed. Just push the seeds into the soil where they are to grow. More: Learn how grow calendula in the Vegetable Encyclopedia.
Another way to make use of space: grow vertical. Choose a vine, such as pole beans, which will happily climb a bamboo teepee. My favorite is the Italian heirloom TrionfoVioletto, available from Botanical Interests, among other seed catalogs. This ornamental and edible plant has lush green foliage with purple undersides. By midsummer, a multitude of lavender flowers appear, followed by thin, purple-podded beans. Pole beans are easy to start from seed, planted right where they are to grow. More: Learn how grow beans in the Vegetable Encyclopedia.