Frost Date Chart

The chart below shows the last and first frost dates for each USDA Hardiness Zone. This information is useful both in terms of knowing when to sow seeds as well as figuring out how late in the season you can plant perennials, trees, and shrubs.

Please note that the dates on this chart are approximate. Most years, the first and last frost will fall within two weeks of the date on the chart, but some years, we get a very early frost or a late snow storm that throws the dates off. Use your discretion (and your local weather forecast!) along with this chart to plan your seed starting and planting.

January 31st (sometimes earlier)

Iris Borers

 Iris borer, in its larval stage, which does the most damage to plants.

Courtesy Missouri Botanical Garden PlantFinder www.mobot.orgIris borer, Macronoctua onusta Iris borer moths lay their eggs on the foliage of irises in late summer and early fall. The eggs overwinter on old foliage, and emerge in the spring as tiny caterpillars that tunnel into the newly emerging foliage. Throughout the summer, they they tunnel their way down to the rhizome, growing to about two inches long. By the time they are fully grown, they start tunneling into the rhizome. Once they are ready to pupate, they leave the rhizome to dig into the surrounding soil. In late summer, they emerge as moths, and the cycle begins anew.The first signs of iris borer damage are difficult to recognize unless you know what to look for. Tunneling through the foliage that looks waterlogged is a sure sign of iris borers. If the tips of the foliage turn yellow, and then start to look dead, that's another sign. And, if the base of the stalk has become yellowish-brown and mushy, and has a sickly odor, they have gotten into the rhizome and rot has set in. If you are digging irises to divide or move them, you may notice holes in rhizomes as well.In some cases, the plant will, surprisingly, live on if rot hasn't set in. Most likely, it will bloom less, or not at all. In many cases, however, we aren't as lucky and the caterpillars cause so much damage that the rhizome rots completely. Monitor your plants closely throughout April and May. If you begin to see signs of tunneling, prune off the affected foliage below where the damage occurs. The caterpillar, still quite small, will be trapped inside the section you've removed, and you can destroy. If you are noticing rot at the base of the stalk, dig up the rhizomes to inspect them. If you see tunneling into the rhizome, but are unsure whether or not the borer is still inside, soak the rhizome in water. The borer will drown. Inspect the rhizome. If the damage isn't too bad, cut away the damaged areas, let the cut dry for several hours, and replant. The key here is tidiness. If there is no leftover foliage in which the eggs can overwinter, there will likely be no caterpillars to contend with. Always remove old stalks and foliage after the plants are hit with a frost. If iris borer is a persistent problem, consider planting resistant varieties. While iris borer can attack any type of irises, it is less likely to bother with siberian irises, because the rhizomes are planted deeper in the soil.

Seed Starting Equipment

There are several good reasons to start your own plants from seed. You have a wider range of varieties open to you than you would have if you purchased plants from your local nursery. It's much more economical. For the price of one plant you can buy a few packets of seed, resulting in dozens (and up to hundreds) of plants. And, it's fun. There's nothing quite as rewarding as watching a seed sprout and grow, and eventually produce beautiful blooms or delicious vegetables.

However, there are a few things you need to be successful with indoor seed starting. None of these items are expensive, and many of them can be used year after year.

Lights: The best lights for your indoor seed starting set up are the shop lights that you can find in any home center or hardware store. These are the four-foot long lights that you hang from the ceiling or a shelf with chains. They are very inexpensive, and are a good choice because you can fit a couple of flats (or several individual pots) under each light. Even more importantly, you can adjust the height of your lights over the seedlings. This is important because your lights should always be two to three inches above the tops of your seedlings. This will ensure that they get enough light and you won't end up with thin, scraggly seedlings. The chains make it easy to keep adjusting your lights during the weeks that your plants live indoors.

Seed Starting Mix: The key in growing successful seedlings is the same as the key in growing successful garden plants, and that is good quality growing medium. In the case of seeds, you need to start with a sterile, soil-free mix. There are several good bagged products that are composed of sphagnum peat and perlite. You can also make your own mix, which is a good option if you are doing a lot of seed sowing. Do not use garden soil, and potting soil is not a good option either. Garden soil is far too heavy and contains pathogens that can result in poor health or death for your seedlings. Potting soil can also contain pathogens, but, depending on the brand, can also be too heavy or contain items like sticks and pebbles. Some even contain chemicals that inhibit germination. A sterile, soil-less mix is what you need.

Containers to Sow In: There is a huge variety of containers that you can choose from when you decide to start from seed. You can use plastic or pressed peat flats for starting a large number of seeds that you will prick out and transplant later. You can buy plastic cell packs, which many of us are familiar with. You can buy individual peat pots or peat pellets, which you put in the ground along with the plant. You can even use recycled materials from around the house, such as individual yogurt cups, egg cartons, or milk cartons. What you use will depend on both your budget and what types of seed you are working with. Each type of container has its strengths and weaknesses, and it seems that every gardener has their own favorite kind of container to start seed in.

Plastic Bags or Covered Trays: When you first plant your seeds, they will need a period of high humidity and even moisture to ensure germination. The best way to guarantee that the soil stays moist is to cover your flat or pot with clear plastic, creating a miniature greenhouse. You can buy kits at the home center or nursery that consist of a bottom tray and clear plastic dome for this purpose, and these are very convenient. You can also buy large zipper bags and place your pots or small flats inside, keeping the plastic away from the soil so it doesn't impede germination.

Misting Bottle and Watering Can or Shallow Tray for Bottom Watering: Watering is a tricky proposition when you first plant your seeds. If the flow of water is too heavy, your seeds will float away or end up in corners of your flats or pots instead of in the center. Your best options early on are to either mist each container well, or to set the entire container in a pan of water for bottom watering. Once your plants have developed roots, a standard watering can will work fine. One with a "rose" attachment is even better.

Plant Markers: You'll need to keep track of what you planted, and plastic or wooden plant markers or tags are the best option for this purpose.

Larger Containers for Transplants: If you are growing large plants like tomatoes, you may need to pot them up into larger containers before they're ready to plant out into the garden.

Fish Emulsion: Once your plants develop their first true set of leaves, they'll need to be fertilized. The soil-less mix you started the seeds in doesn't offer any nourishment to your plants. Once every two weeks, water your seedlings with fish emulsion, which has been diluted by ? of its normal recommended dosage.

Seeds: The fresher the better, but if they are a year or two old just sow extras in case they don't all germinate.

Other Options: There are a few other items that can make your seed starting set up work easier or more effectively. Other items you might want to add are a timer for the lights (so you won't forget to turn them on or off), a fan to increase air flow and help prevent fungal diseases, and a heat mat for heat-loving seedlings like peppers and eggplants. With these inexpensive items, you can ensure that your plants will get off to a great start.

What is Organic Gardening?

Organic gardening has been described as several things: chemical-free gardening, Earth-friendly gardening, natural gardening are just a few. And it is all of these things, but these phrases tend to be so ambiguous they end up causing confusion. For example, “chemical-free gardening” is a total misnomer, because whether you are using organic or synthetic fertilizers and pesticides in your garden, they are all “chemicals.” “Natural gardening” espouses images of weeds run rampant and hornworm-infested tomato plants. “Earth-friendly” gardening works, except that everyone has a different view of what they consider to be “friendly” to the planet.

So, to try to narrow it down, organic gardening consists of three main tenets: Feed the soil.Focus on prevention.Use the simplest solution first.

The soil is the basis for everything that grows in our gardens. If the soil is nutrient-weak, compacted, or devoid of beneficial microorganisms, it will not support healthy plants. You can try to “fix” it with fertilizers, but it will never grow as well as a plant grown in healthy, rich, crumbly soil. By feeding the soil, you provide plants with a good foundation for healthy growth. Plants that are healthy are less likely to be bothered by pest and disease problems.

So, how do you feed the soil? By adding organic soil amendments, such as compost, manure, chopped leaves, and mulches in and onto the surface of the soil. A soil test will inform you of any mineral deficiencies, and explain how to remedy the situation.

There are several things you can do to help your plants thrive, which will limit their susceptibility to pest and disease problems. Pay attention to the plants' light, moisture, and soil preferences. Match the plant to the right site, and it will grow more robustly and be better able to resist pest and disease issues.Give your plants some breathing room. Fungal diseases run rampant when plants are planted too closely. Susceptible plants, such as lilacs, monarda, phlox, and roses should be given a site with plenty of space for air to circulate around the foliage.Purchase and plant disease-resistant varieties. Maintain a clean garden. Remove diseased foliage from the area. Pick up fallen fruit. Pay attention to pruning; powdery mildew and blackspot can be thwarted by opening up the plant and cutting back diseased or weak stems. Observe, observe, observe. If you catch a problem at the beginning, such as a case of blackspot or an aphid infestation, you can nip it in the bud right away and be done with it. It is much easier to deal with it in its early stages than having to fight off a full infestation. Check your garden regularly, daily if possible, to watch for problems.

When you see the arsenals of lawn and garden chemical available at your local home center, it seems so simple: if you have a problem with aphids, buy a chemical to kill them. But the fact of the matter is that taking care of most garden problems is simple, and requires much less drastic measures than drenching your garden with chemicals. For example, the first course of action when one notices aphids in the garden should be to try to spray them off your plants with water from the hose. Usually, this will solve the problem. The next option, if the water isn't enough, would be to concoct a simple, natural, home-made spray to treat the problem. Very, very rarely will a problem actually require a chemical spray. The most effective option, especially in terms of beetles and caterpillars, is to regularly pick them off with your hands and kill them. This is tied to the previous point; by regularly observing your garden, you'll be able to head off problems before they become a big deal.

Organic gardening is not difficult, and it isn't complicated. What it requires is an observant eye, an appreciation of all of the creatures that live in your garden, and the determination to deal with problems as they arise. And, think about it: it's much more pleasant to stroll through the garden, picking an occasional cabbage worm off of the kale, than to suit up in protective gear and start spraying insecticides.

Costoluto Genovese

"Costoluto Genovese." The name just sings of rich sauces, rolling off the tongue with a fullness that perfectly matches this tomato's flavor. Haling from Italy, where it is the favorite tomato for sauces and concentrates, the Costoluto Genovese dates back to before the nineteenth century.

It is an attractive tomato, with ruffled, round eight to ten ounce fruits that have a slightly flattened shape. The skin and flesh of this tomato is deep cherry red. Costoluto Genovese has a Brix rating of 5, well balanced with a bit of acidity, which makes it a great tomato for sauces or pastes. Surprisingly, it is also a fairly good tomato for fresh eating; very tasty sliced onto a sandwich.

Costoluto Genovese is an indeterminate variety, producing fairly regularly and providing a fairly early crop.

How to Grow Turnips

Turnips are easy to overlook when planning your vegetable garden. They're not flashy, like tomatoes. They're not exuberant, like squashes, with all of their vining and blooming. No, turnips are quiet, respectful little plants that pretty much keep to themselves and avoid causing the gardener too much trouble.

So, why don't more people consider them a "must," the way we do tomatoes? I think it's mostly because turnips are misunderstood. I mean, what do you do with the turnips once you grow them? And do they even taste good? We'll get to that, but first let's take a look at what they are and how to grow turnips in your organic garden.

Turnips are root vegetables, and part of the mustard family of plants. They are related to radishes, arugula, and rutabagas. They are generally harvested in the spring and fall. The entire plant is edible; the root can be eaten raw or cooked, and the greens can be eaten like any other leafy green. They are high in vitamin C, vitamin A, and fiber.

Turnips are easy to grow from seed sown directly in your garden. Plant the seeds four to six inches apart in soil that is loose and well-drained. They require very little care other than regular watering to prevent the roots from getting tough and woody. Cabbage worms can be a problem, so check for signs of them often during peak season, usually late spring. Look for tell-tale holes chewed into the foliage, and scour the foliage regularly for the small green worms. Remove them when you see them by hand-picking and dropping them into a cup of soapy water. If you're seeing a large infestation, you can treat your plants with Bt to take care of the worms.

Turnips should be harvested small. They have the best, mildest flavor when they are about two inches in diameter. If left to get larger, they can become rather woody and unpleasant. The greens should be harvested young as well, a few from each plant if you want to be able to harvest the turnips later on.

You'll find several ideas for how to prepare turnips from the About.com Food and Cooking Guides linked below this article. It really is a useful vegetable, adaptable to a wide range of recipes.

So, when you're planning your spring or fall garden, give turnips a chance. They're pretty, they're good for you, and (best of all) they are really easy to grow.

Tips for Raised Bed Gardening

Raised beds are great: the soil in them warms and dries out earlier in the spring than regular garden beds, so you can get planting sooner. They allow us to garden without fighting stones and roots, and the soil in them stays perfectly fluffy, since it doesn't get walked on.

Of course, there are a few drawbacks: in hot dry weather, raised beds tend to dry out quickly. Roots from nearby trees will eventually find their way into your nice, nutrient-dense soil. Roaming cats may find the nice, fluffy soil attractive for their own reasons. But these few drawbacks are easy to avoid with a little planning and prevention.

Ten Tips for Raised Bed Gardening

Don't ever -- ever! -- walk on the soil.

The biggest advantage of raised bed gardening is the light, fluffy, absolutely perfect soil you're able to work with as a result. When you build your raised beds, build them so that you're able to reach every part of the bed without having to stand in it. If you already have a raised bed, and find that you have to walk on parts of it, consider installing strategically-placed patio pavers or boards, and only step on that rather than on the soil.

Mulch after planting.

Mulch with straw, grass clippings, leaves, or wood chips after planting your garden. This will reduce the amount of weeding you'll have to do and keep the soil moist.

Plan your irrigation system.

Two of the best ways to irrigate a raised bed are by soaker hose and drip irrigation. If you plant it ahead of time, and install your irrigation system before planting, you can save yourself a lot of work and standing around with a hose later on.

Install a barrier to roots and weeds.

If you have large trees in the area, or just want to ensure that you won't have to deal with weeds growing up through your perfect soil, consider installing a barrier at the bottom of the bed. This could be a commercial weed barrier, a piece of old carpet, or a thick piece of corrugated cardboard. If you have an existing raised bed and find that you're battling tree roots every year, you may have to excavate the soil, install the barrier, and refill with the soil. It's a bit of work, but it will save you tons of work later on.

Topdress annually with compost.

Gardening in a raised bed is, essentially, like gardening in a really, really large container. As with any container garden, the soil will settle and get depleted as time goes on. You can mitigate this by adding a one to two inch layer of compost or composted manure each spring before you start planting.

Fluff the soil with a garden fork as needed.

To lighten compacted soil in your raised bed, simply stick a garden fork as deeply into the soil as possible, and wiggle it back and forth. Do that at eight to twelve inch intervals all over the bed, and your soil will be nicely loosened without a lot of backbreaking work.

Cover up your soil, even when you're not gardening.

Add a layer of organic mulch or plant a cover crop (read more about that below) at the end of your growing season. Soil that is exposed to harsh winter weather breaks down and compacts much faster than protected soil.

Plant annual cover crops.

Annual cover crops, such as annual rye grass, crimson clover, and hairy vetch, planted at the end of the growing season, will provide many benefits to your raised bed garden. They provide nutrients to the soil (especially if you dig them into the bed in spring), reduce erosion, and (in the cas of vetch and clover) fix nitrogen in your soil.

Think ahead to extend the season.

A little planning up front can enable you to grow earlier in the season or extend your growing season well into the fall. Consider installing supports for a simple low tunnel or cold frame, and you'll have minimal work when you need to protect your crops from frost!

Consider composting directly in your raised bed garden.

Worm tubes, trench composting, and dig-and-drop composting are all methods you can use to compost directly in your raised bed garden. You'll be able to enrich your soil without ever having to turn a compost pile.