Question by little lamb: I live in Phoenix, AZ. What’s the best way to grow your own herbs?
I would like to grow basil, thyme, rosemary, sage, oregano, parsley, marjoram, and chives. Should I grow them indoors? They seem too delicate to be outside.
Answer by gardengallivant
The list you give includes woody Mediterranean climate plants that will do well in Phoenix outdoors. Rosemary is a shrub that does not like to be in wet or humid conditions. Rosmarinus officinalis does best it a rather dry light, sandy loam. On a chalk soil it grows smaller, but is more fragrant.
Oregano and thyme are winter hardy herbs that need full sun. Oregano creeps so can grow along steps or rock walls easily. It will form a mound that can be sheared into shape. The major species include Origanum marjorana also known as sweet marjoram and Italian oregano O. vulgare ssp. hirtum.
O. marjorana can be tender but O. vulgare is hardy. They need a well drained, alkaline soil of no more than average fertility to flourish. They can become bitter with to much fertilizer and grow lax, spindly foliage developing poor fragrance because the oils are not made & stored properly when growing quickly.
Thyme is an enormous family divided into bush and creeping types. Orange balsam blooms first while English and Wedgwood bloom last in the bush category.
They are choosy about their soil. Thyme are shallow rooted so are easily frost heaved completely out of the soil in cold climates. In humid or damp areas they can develop rot.
They like sandy or rocky soil that is 1/2 sand and 1/2 average loam. They do not like acid soil so need lime or oyster shells added in those conditions. They need an inert mulch layer to keep surface moisture down but offering a chance to self-layer the lateral branches. An organic mulch will work because you are in an arid area.
Bush thymes may be trimmed in spring or after flowering to as much as 50% of their height or they can do well with several light shearings removing less than an inch at a time. Heavy shearing should never be done in summer. They require a dense mound of foliage to protect their main branches from desiccation in winter.
Basil is tender and needs much the same conditions as tomatoes. They like a dry surfaced, well drained soil. This means the water should be infrequent on the surface but available at depth. This means they do very well with flood irrigation or soaker hoses.
A bark or gravel mulch aids in keeping the surface dry. Thick organic mulch or sawdust keep the soil too cool for me in zone 7b but might work well for you. Poor soils impart a clove-like flavor while rich soils and excess moisture produce the licorice flavor.
Some basils are leggier than others so are less attractive outside the kitchen garden. Those with the best shape include Dark Opal, Spice, and Krishna.
Chives, Allium schoenoprasum, like a richer loam that stays moist. In hot areas they need shade at midday. These definately need an organic mulch. They may be a winter crop for you.
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