From: DK Books - Herbs
Shopping for new plants can be very enjoyable, but it is easy to get carried away by the latest, prettiest, most colorful new cultivar or "must have" and spend your budget in an instant. Browsing at flower shows or at nurseries, however, is free and will stimulate many new ideas.
Where to Buy
Many people buy their first herb from a supermarket; most likely an intensively produced basil or parsley. At the other extreme is the specialist nursery that stocks many hundreds of cultivars from one or two genera. Happily, in between there are the plant nurseries staffed by knowledgable and enthusiastic professionals, only too happy to help.
Most nurseries try to display their stock when it is looking its best, which can mean in full flower and perhaps not the best time for planting. Ask the staff what would be best and then, as your skills and knowledge grow, you will also feel more at home with the specialists.
What to Look for
Space your herb shopping trips over the year as you will soon discover which nursery consistently carries a comprehensive but changing range as well as demonstrating what looks good at different times of the year.
Look for healthy, younger plants whose foliage should be clean, unstained, and free of excessive damage. The compost should be moist but not waterlogged and the surface should be weed free. Clean pots are indicative of young plants grown in an uncongested space. Make sure the labeling is clear.
What to Avoid
Be wary of buying small plants in big pots as these could have recently being potted up and are not good value. Also avoid plants that look tired, wilted, or have matted roots growing through the drainage holes.
Good Versus Bad Rootballs
A herb should be easy to remove from its pot without damaging the plant or its roots. It will be pest free, just moist and filled with a lose mesh of fine and coarse roots (Image 1).
Such herbs are hard to remove from the pot without damaging the plant. It may be waterlogged or have evidence of pests. The roots may be congested (Image 2).
Avoid Leggy Plants
These may be cheap, but leggy stems are indicative of overcrowing and poor light. Avoid them unless you have the time and patience to nurse them back to health.
Size of Plants
These are very small plants and are a useful way of growing large numbers of identical plants. Often sold by mail order, they need to grow on before being planted out (Image 1).
Price and pot size are closely related, but a large plant can be harder to establish and needs care over periods of drought. Smaller plants may need transplanting (Image 2).
Large Mixed Plantings
These are a useful way of getting an instantly harvestable selection of herbs. They need regular trimming and dividing or replanting after a season or two (Image 3).