Marigolds & Nasturtiums
By Bill Goff & Karel Ulizio ©2015
Penn State Master Gardeners
Marigolds and nasturtiums may have grown in your grandparents' gardens. Although a walk through your local garden center might make them seem irrelevant next to the newest, latest and greatest introductions from large nursery companies, don't forget these old favorites when planting your garden.
No annual garden should be without the cheerful, bountiful blooms of marigolds (Tagetes species). Marigolds bloom early in the summer and continue non-stop up to the first hard frost in the fall. They are easily started from seed and are a favorite of pre-school children and nursing home residents who can eagerly watch the progression of seeds to plants to flowers.
Marigolds are mainstay for beds, containers and window boxes. Their pungent scent repels many insects and is unappealing to deer and rabbits. Culture for this old-fashioned plant is easy. Select an area with good drainage, adequate moisture and full to half-day sun. Young plants should have their first flowers pinched off to encourage more blooms and a bushier plant. Deadhead, or remove spent blooms, to ensure continuous flowering.
Mites, aphids and slugs can occasionally be a problem, but the vigorous growth of marigolds typically overcomes insect problems. Keep the soil around them free of debris and clip off affected leaves at the first sign of damage. More severe infestations can be controlled with a spray of water or insecticidal soap.
* African - Tall, up to 3 feet and may require staking. They produce large orange and yellow flowers.
* French - Range from 5 to 18 inches tall. Topped with 2-inch flowers with copper, orange and yellow flowers.
* Signet - Feature lacy foliage and small, edible red, orange and yellow flowers.
* Triploid or mule - Sterile hybrids of African and French marigolds.
Nasturtiums (Tropaeolum majus) are another old-fashioned charmer. They are easy to sow and grow and are relatively pest- and disease-free. Nasturtium flowers and leaves are edible and are the perfect plant to introduce into an edible landscape. The Latin translation of nasturtium is "nose twist," referencing its pungent smell and taste.
Nasturtium is grown as an annual, although a few seeds always escape the fall harvest. They poke their tender green shoots up every spring in places of their own choosing. Nasturtium's growing habit is to scamper along the ground or flow down a planter in cascades of vermillion, peach, tangerine, mahogany, rose, butter or cherry. Their leaves look like tiny water lily pads, typically a rich shade of deep green or blue-green. Newer variegated and speckled leaf varieties add panache to this plant that is already full of charm.
They come in trailing and compact varieties. Trailing nasturtiums add a beautiful touch to window boxes and hanging baskets. They are prolific, and respond well to cutting if they begin to encroach upon neighboring plants. Compact varieties are suited for creating drifts of color along the front of the border.
Nasturtiums grow best sown directly into the soil. Space them 10-12 inches apart, in full sun, after the threat of a frost has passed. If planted in very rich soil, they may produce foliage at the expense of flowers, so amend the soil lightly.
One sure fire way to impress your summer garden guests is to add peppery-flavored nasturtium blossoms and leaves to a salad. The flowers make beautiful garnishes on cakes or soups. The leaves can be chopped and added to dips. The flavor of both flowers and leaves become spicier as summer's heat intensifies.
Nasturtiums hail from sunny South America. Native people used the leaves medicinally as teas for several ailments, including as an antiseptic. Nutritionally, they are high in Vitamins A, D and C.