Catnip

Sow seed indoors a few weeks ahead of your last frost date and grow the seedlings on in a sunny window. Move them out after frost danger passes, giving each plant about 3 feet of room, since a mature clump can grow up to 3 feet tall and just as wide. An indoor start puts an established, rooted plant in the ground with enough of the season left to reach the full bloom the plant is harvested at. Catnip can also be propagated by division of established plants if you already have a clump.

Lift established clumps as growth resumes, shake the soil off, and cut the root mass into sections with a spade or sharp shears before replanting them at the depth they were growing. Catnip is a vigorous but short lived perennial that spreads by short rhizomes, and the center of an old clump thins and declines - dividing it restarts the planting from the young growth at the edges.

Set an ornamental bird cage or a cage of wire mesh over young plants and leave it in place while the clump establishes. Where cats are persistent, growing catnip in a hanging basket keeps it out of reach altogether. Roaming cats damage catnip mainly by rolling on the plant and breaking the stems, and a young plant has little growth to spare.

Cut whole stems once the plant is in full bloom and hang them to dry in a cool, well ventilated location. Once dry, strip the leaves off the coarse stems and store them in sealed containers. The flavor and aroma of catnip are at their peak when the plant is in full bloom, so a cutting taken then carries the most of what you are drying it for.

After the first flush of flowers fades, shear the flower spikes back over the whole plant. Pinching the plant back through the season as well keeps it compact instead of sprawling and weedy. Cutting the spikes before they set seed sends the plant back into growth rather than into seed production, which is what drives the repeat bloom and the second cutting of leaf.

Cut the plant all the way to the ground in autumn once flowering is finished. It dies back to the ground over winter anyway and sends up fresh stems from the crown in early spring. Catnip reseeds readily and can become weedy, and taking the top growth off before the seed heads shatter is what keeps a planting from spreading into ground you did not intend to give it.