Cutting Garden Annuals to Grow from Seed
Starting flowers from seed is a fun early spring activity and can save you a lot of money. If you want to grow flowers for cutting, it’s also a necessity.
Garden centers offer plants with broad appeal, so you’ll rarely find annuals such as phlox drummondii, salvia horminium, zinnia Queen Lime Blush or amaranth Oeschberg. Yet these are the annual flowers that will elevate your garden and and all your summer bouquets from good to great. Read on to learn about 10 of my cutting garden favorites that are easy to grow from seed.
Easy Annuals for Summer Bouquets
I am not a fan of the dwarf ageretums used as bedding plants, but the taller varieties such as Blue Horizon are completely different. They grow 24-30” tall and have dark stems, fuzzy blue flower heads and a long vase life. Sow the tiny seeds indoors under lights, 6-8 weeks before the last frost. Remember not to cover them with soil as they need light to germinate. When the seedlings have two sets of true leaves, transplant them to individual cells. In the garden, space plants 12” apart and harvest when flowers are ¾ open. Keep the plants deadheaded and they will flower until frost. No support needed.
For best results, bachelor’s button seeds should be planted directly into the garden. The plants grow best in cool weather, so sow the seeds in early spring as soon as the ground can be worked. Cover seeds lightly and keep the soil surface moist until plants emerge. When the seedlings have one or two sets of true leaves, thin them to stand 6” apart. Plant two or even three sowings to extend the harvest season. Pick sprays when most of the flowers are at least half open. You may find the plants need support to keep the stems from flopping.
For best results, plant seeds directly into the ground after the last frost. If chipmunks and birds make off with the seeds, you will need to start your sunflowers in pots. Transplant when young and disturb the roots as little as possible. To encourage more stems, pinch off the top of each plant when it has three sets of true leaves. To extend the cutting season, plant varieties with different bloom times — or make a second sowing 2-3 weeks after the first. Branching varieties are best for cutting. Space plants 12-18” apart. For cutting, I prefer sunflowers with 4-5″ diameter flowers, such as Jade (shown above). Sunflowers don’t need support as long as they are not exposed to high winds.
There are dozens of pretty varieties to choose from in a wide range of colors and flower styles. Direct sow seeds after the last frost. Barely cover them and keep the soil surface moist until seedlings emerge (1-2 weeks). Thin as needed so the plants stand about 12” apart. Cut stems when flowers first open, before the petals have completely unfurled. I prefer the singles, but there are also doubles and semi-doubles. Taller varieties (4-feet or more) may need staking.
Direct seed after the last frost. Cover lightly and keep the soil surface moist. When true leaves appear, thin to 12” spacing. (Keep a few extra plants around to replace those that don’t make it.) Seeds may also be sowed under lights, but start them no more than 4 weeks before the last frost. Plants that get root bound may never recover. Pick zinnias when the flowers are fully open and stems have stiffened. Every variety in the “Queen” series (shown above) is gorgeous.
Ammi majus and Dara
These are cultivated cousins of Queen Anne’s lace. The lacy flowers and feathery foliage make every bouquet better. The flowers of Ammi majus are white or pale green while those of Dara (shown above) are a mix of white, pink and burgundy. Direct sow seeds after the last frost. To extend the cutting season, make two sowings, several weeks apart. The seeds may also be started indoors under lights. When transplanting to the garden, space the plants 6-12” apart. Be prepared to provide support stakes to keep them upright.
My favorite amaranths feature upright, burgundy flowers and dark foliage (look for Red Spike or Oeschberg). Copper-colored Hot Biscuits is also good. There are also cascading types with red, green or coral flowers. Amaranth seed is very fine and best started indoors under lights, 4 to 6 weeks before the last frost. Or direct sow, barely covering the seed. In the garden, thin or transplant so seedlings are 12-15” apart. Pinch when plants are young to encourage bushy growth and smaller flower clusters (better for cutting). Plants continue growing until frost and usually don’t require support.
This type of phlox grows just 18″ tall and produces small flower clusters. It adds a relaxed, country feel to mixed bouquets. You can choose from lots of beautiful colors, including antique hues such as Cherry Caramel. Direct sow seeds in early spring, covering lightly but completely as seeds need darkness to germinate. Thin seedlings to 8-12” apart, taking care not to disturb the roots. Harvest stems when at least half the flower cluster is fully open. No support needed.
Also known as Salvia viridis, this plant is grown for its colorful, leaf-like bracts. Seeds are usually sold as a mix of purple, pink and white, but are sometimes available in separate colors. (I find purple to be the most vigorous and showy). Start seeds indoors under lights, 6 to 8 weeks before the last frost. Do not cover them as they need light to germinate. Transplant when seedlings have 2 or 3 sets of true leaves. Harvest at any time. Plants will tolerate a light frost and continue blooming well into the fall. Stems are stiffly upright, so need no support. They last for 10 days or more in a vase.
Also known as feverfew, this is my favorite bouquet filler. The 30” tall plants have lacy foliage and produce clusters of little white buttons with yellow centers. Seeds are small, slow growing and need light to germinate. Start indoors under lights, 6-7 weeks before the last frost. Transplant into separate cells when seedlings have 2-3 sets of true leaves. Keep plants deadheaded and they will continue flowering to frost. Plants may self-sow and may also be perennial in zones 5 and warmer. Look for Tanacetum parthenium ‘Tetra White’ (shown above) and lime-leaved Tanacetum aureum. No support needed.
I find “cockscomb” celosias ugly, but the ones known as “pampas plume” are a new favorite. Their feathery, slightly fuzzy flowers are good weavers in arrangements. Newer varieties include soft hues such as the one shown above, called Sylphid. Start the seeds indoors under lights, 6 to 8 weeks before last frost. Don’t cover them as they need light to germinate. Transplant seedlings into separate cells once they have one or two sets of true leaves. Move outdoors after danger of frost, spacing plants 6 to 12” apart. They will grow 2 to 3 feet tall with branching, 12” stems. No support needed.
Here are several more annuals that often make their way into my cutting garden: nicotiana alata ‘Lime Green’, love-in-a-mist (Nigella damascena), sweet peas, snapdragons, scabiosa, verbena bonariensis, larkspur, kiss-me-over-the-garden-gate (Polygonum orientale), and China asters.
Tips for Success
Cutting garden annuals always perform best in full sun. Most will bloom all summer if you deadhead weekly. Removing spent flowers also minimizes disease problems and deters earwigs and other pests.
Always cut your flowers in the morning or evening and bring a bucket of clean water out into the garden with you. Scissors can crush stems and inhibit water uptake. Flower farmers usually prefer a sharp knife for clean, quick cuts.
If you plan to grow flowers from seed, be sure to check out the selections offered by Johnny’s Selected Seeds and Select Seeds. For an excellent guide to growing flowers from seed, I recommend: The Gardener’s A-Z Guide to Growing Flowers from Seed to Bloom.