Hi Susan, Coriander like most of the herbs particularly the leafy ones do best on a complete fertilizer, but one high in nitrogen. I use the popular Tropic or CK88 granular fertilizer for beds and a soluble one like Aquasol. In fact you can expect to see a positive response from a deficient plant well within a week using a good soluble complete fertilizer; .as soon as deficiency symptoms start to appear I would water the plants weekly with the soluble fertiliser. Deficiency symptoms in coriander are very obvious from yellowing to even reddish leaves in severe cases. There are definitely different types/ cultivars of coriander, depending on the seed source. There are also two distinct types the more leafy cilantro type and the quicker seeders type coriander. However both go to seed/bolt easily in the warmer weather. I always continuously plant, from weekly in summer to monthly in winter to maintain a continuous supply of lovely leaves without flowers. Plants in partial shade tend to grow taller with thinner stems. Interplanting with other herbs or close planting usually negates the need fro supports. Of course the best way to overcome need fro support id to harvest regularly, which coriander loves. Hope this helps. John Bee Master Gardener.

- John Bee