Fertilizer basics for the vegetable garden
Many of our vegetable gardens are coming into their own now, offering up baskets of beans, tomatoes, corn perhaps and enough zucchini to feed a small Third World country. And many vegetable gardeners are contemplating their next step, a planting progression to take the harvests into the fall by starting some cooler-weather crops such as spinach, lettuce, bok choy and the like. It’s also a good time to take a moment to consider fertilizer options.
National Garden Bureau member Bonnie Plants offers some advice on the basics of fertilization for your home vegetable garden. Plants grow using energy from the sun combined with nutrients taken from the soil. Because the organic matter in soil holds nutrients like a sponge until they are needed by plants, soil that is fertile, well drained, and regularly enriched with compost often holds a reasonable supply of plant nutrients. Unimproved, newly cultivated soil is usually low in organic matter, so it is also low in nutrients, says Plants.
All edible plants remove some nutrients from the soil, and some have such huge appetites that they quickly exhaust the soil (and then produce a poor crop) without the help of fertilizer. A soil test will help determine the pH and enable the gardener to choose which fertilizers work best with their soil. Acid soils tend to inhibit the plant’s ability to absorb nutrients. Fertilizer is especially helpful early on, when plants are making fast new growth, especially import to get those fall crops going.
You can mix fertilizer into individual planting holes, work it into furrows, or use a turning fork to mix it into beds. You can also apply a liquid fertilizer every week or two for a fast-acting extra boost of nutrition. Always follow the rates given on the fertilizer label when deciding how much to use. Too much fertilizer can be worse than too little, advises Plants. Overfed plants often grow huge, yet bear a light crop late in the season.
With experience, you will learn how to match fertilizer amounts with plants’ needs for your climate and soil. Onions, tomatoes, sweet corn and vegetables grown in containers respond to special fertilizing techniques and long-lasting, slow-release fertilizers, but most crops grow well if you simply mix a balanced fertilizer into the soil as you set out the plants. Use the lists below to help estimate the fertilizer needs of your favorite crops:
• Light feeders often benefit from a small amount of starter fertilizer but require no additional feeding when grown in soil that has been enriched with compost: Bush beans Mustard greens Peas Southern peas Turnips
• Moderate feeders often need good drainage and moisture-holding mulch more than they need fertilizer. Avoid using organic fertilizers made primarily from processed manure when preparing the soil for beets, carrots, and other root crops. Manure can contribute to scabby patches on potato skins and forked roots in carrots and parsnips. Beets Carrots Okra Pole beans Potatoes Sweet potatoes
• Heavy feeders are often highly productive plants, so a few minutes spent mixing in fertilizer before you set out plants is time well spent. Plants often grow slowly in cooler weather. Some heavy feeders also respond to second helpings later in the season. Broccoli Brussels sprouts Cabbage Cantaloupe Cauliflower Corn Cucumbers Eggplant Kale Kohlrabi Onions Peppers Rhubarb Squash Tomatoes Watermelon
Lynette L. Walther is the recipient of the Garden Writers Association’s Silver Award of Achievement, and she gardens in Camden. Got questions, or comments? Visit her blog, and join in the conversation at: gardeningonthego.wordpress.com or ”friend” her on Facebook to see what’s new in the garden day-by-day.