There are about a dozen different ways to pronounce 'Nasturtium', the correct way, in my version of English anyway, is 'Nuh Stare iam', some tell me that is incorrect, but it's how I pronounce it - how do you say it ? As there are a dozen ways to pronounce it there are also about about different way to use this workhorse of the garden realm. There are also about 80 different species of Nasturtium.
In the kitchen Nasturtium is also a player and is used in many recipes ranging from salads, garnishes, pestoes, dressings and vinegarettes, omelettes nad souflettes and is chopped up and added to many cheeses. For culinary purposes it is considered a cress, like watercress and produces an oil very similar to that of watercress, but with a peppery kick.
Planting and Growing Nasturtium
Although there are many species of Nasturtium there are two types so far as grow habits are concerned. The first is trailing or climbing nasturtium, which is favored by some as it is easily trained to grow up a trellis or fence, but can also be left to sprawl across the ground. The second are bush varieties that grow in loosely compacted mounds.
Nasturtium is best started by direct seeding as it does not transplant well. If you plan on buying nursery starts for transplant be sure to get more than you will need as chances are some will not survive. Your planting site should be in full sun, partial shade will suffice with reduced flowering.
Soak the seeds overnight in room temperature water the day before planting to soften the hull a tad, some gardeners will also nick the seed to allow water to penetrate more readily and expedite germination. To nick the seed, scrape one side of the seed with a nail file or similar tool until the lighter interior seed coat shines through. If you break through just toss the seed.
Sow seeds directly into the soil after the last anticipated frost date in your area, they are not frost tolerant at all. Keep the ground reasonably moist, not soaked just moist. Nasturtiums are not overly picky so far as soil is concerned so long as it is well drained. For best results work modest amounts of compost into the ground. Plant the seeds 3/4 to a full inch deep. Spacing depends on the variety so you are advised to consult the seed packet of the type you are planting, most will advise 3 inches apart. The seeds should germinate with 7 days under optimal conditions, but sometimes take twice that long. If all goes well you may end up with more than you want or more than is advisable for the area designated for Nasturtium so you may have to thin the plants to allow for an 8 to 10 inch circumfrance around the base of the young plants, if all continues to go well they will eventually fill in that space.
If you plan on using the leaves in the kitchen, they are tastier if kept well watered, once again don't drown them just water them well, especially during the summer heat. Heat stressed plants generally produce foliage and flowers that are stronger flavored, more pungent and sometimes unpalatable.
If plants begin to wilt or become even a little leggy during the summer months, cutting them back slightly can encourage new growth for the remainder of the season.
Both foliage and flowers can be harvested all season long. Younger leaves will naturally be mre tender and are prized for their culinary attributes. The flowers, flower buds and seed pods are edible as well. The seed buds are sometimes pickled and served like capers, sopme call them 'poor mans capers' or 'capuchin capers'.