Herbs That Can Be Grown Together in a Hydroponic System

Hydroponic Benefits

• The term hydroponic gardening was first used in the 1920s. However, it wasn't until the 1950s that hydroponic farming became more widespread and commercially viable. Today this growing method is widely used for vegetables, such as lettuces, herbs and flowers. Hydroponic gardening is efficient as it recycles the nutrients in the system. Weeds and pests are minimized, and space requirements and growing times are less than in soil cultivation. Herbs are especially suited to hydroponics because the majority of them are hardy and require the most basic of plant needs.

Solution pH

• The pH of the solution is important for the same reason soil pH supports plant growth. The correct pH encourages nutrient uptake and use while an improper pH can cause the plant to become deficient in certain nutrients. Herbs generally need a neutral to slightly acidic pH. At the lowest range of 5.5 to 6, chicory, mint, parsley and rosemary thrive. Basil and lemon balm grow at slightly higher pH, up to 6.5. Marjoram's ideal pH is just 6, but others, like mustard cress and chives, can go from 6 to 6.5. The herbs that are the most tolerant of higher pH are fennel, lavender and watercress.

Life Span

• Different plants have different growth expectations. In hydroponics, plants are grown closely together; and when one dies, it is best to replace it to preserve the efficiency of the system. Plants with similar growing habits should be placed together to make it easier for the gardener to install and care for the herbs. There are annual, perennial and biennial herbs. Annuals bloom in one season and then die. These include anise, basil, chervil, coriander, dill and summer savory. Perennial herbs, such as chives, fennel, lovage, marjoram, mint, tarragon, thyme and winter savory, will bloom every year. Biennials produce only vegetative growth in the first year and then bloom and die in the second. Caraway and parsley are of this type.

Temperatures

• The majority of herbs can tolerate temperatures down to 40 degrees Fahrenheit. Some are much more tender, such as basil, which cannot withstand temperatures below 50 degrees. The ideal temperatures for herbs are 65 to 70 degrees during the day and 55 to 60 at night. Woodier-stemmed herbs are more tolerant of cool temperatures and can overwinter even in an unheated greenhouse in most climates. Oregano, marjoram, thyme, sage and lavender are some of these types. Rosemary is a temperate plant that can also be grown with cool-climate herbs but may succumb if it experiences freezing temperatures. Soft-leaved plants, such as lemon balm, catmint, basil and cilantro, need warm temperatures above 50 degrees to thrive. In excess heat, however, some herbs bolt or flower rather than produce leaves. Dill, basil and cilantro represent this sort of plant.