End-of-Summer Garden Tasks: Seed Saving, Fall Flowers, Bulb Storage, and Cuttings

Saving Seeds

Saving seeds from most hybrid annuals is disappointing—offspring often diminish in size or color yearly. You can't judge quality until bloom (though some, like Nicotiana "Lime Green," flower true).

Most annual seeds can be gathered, placed in labeled paper envelopes, and stored cool, dry, and dark until spring. Annual ornamental grasses, bishop's weed, winged everlasting, borage, creeping zinnia, tithonia, Johnny-jump-up, bells-of-Ireland, most tree mallows, California poppy, and starflower are all excellent for seed saving.

Late summer is seedpod-ripening time for winter bouquets. Flowers often produce a final vivid flush as autumn approaches, colors brilliant against crisp blue skies.

Fall Flowers for Extended Color

As days shorten, some annuals show surprising strength. Strawflower petals (many Australian natives) resist frost, glowing in early fall sun. Poppy flowers fade but seedpods persist. Flowering cabbages and kales need frost to develop colored leaves. Pansies bloom all winter in mild areas, persist in northern gardens until deep snow. Sweet alyssum flowers deep into fall.

Now is the time to pot geraniums (Pelargonium spp.) for sunny windowsill blooms. Bedding begonias and ageratums can move to pots for flowers until December. Polka-dot plants (Hypoestes phyllostochya) are tropical perennials easily overwintered indoors. Even marigolds bring gold to winter rooms.

Learn autumn plants to add to your garden.

Older books advise pulling geraniums in fall, shaking off soil, and hanging in frost-free storage. Spring: cut back and replant. Results vary, but savings on new plants may justify the effort.

If you have a greenhouse, sunporch, or light garden, take cuttings of annuals for new plants.

Bulb Care for Winter Storage

In cold climates, tender bulbs must be lifted in fall. Dig dahlias after first frost blackens leaves. Cut stems a few inches above tubers, clean soil, dry a few days, then brush off remaining soil. Sort by flower color, store in paper bags/boxes in cool, dry place until spring. Same for gladiolus corms. Don't forget four-o'clocks (Mirabilis jalapa) and canna rhizomes.

Root Cuttings for New Plants

1. Cut healthy stems 3–5 inches long with a sharp knife/razor, just below a leaf node.

2. Remove damaged leaves/flowers and trim bottom leaves.

3. Fill a seed flat or pots with damp sterile mix. Tamp, make pencil holes ¾ deep.

4. Insert cuttings ensuring stem base contacts soil. Firm soil around stem.

5. Create a mini greenhouse: Pot in a plastic bag, sealed with a wire twist. Place in bright, indirect light. Keep moist, not soggy. In 2–3 weeks, tug gently to check rooting. If not rooted, check for rot. If healthy, retry ensuring soil contact. Rooting hormone powder helps.

Geranium Cuttings in Water

Impatiens, coleus, begonias, and geraniums root in water. Once roots appear, add small amounts of sand/soil every few days to prevent tangled roots and stimulate root hairs.

How to Take Geranium Cuttings

Step 1: As summer ends, clip off flower heads.

Step 2: Select healthy, vigorous tips or side shoots.

Step 3: Remove leaves from bottom third to half. Prepare moist potting mix.

Step 4: Dip ends in rooting hormone (optional), insert to just below lowest leaves.

How to Take Coleus Cuttings

Step 1: In late winter, take cuttings from indoor coleus for spring garden plants.

Step 2: Strip lower leaves, place stems in water. Change water 1–2 times weekly to prevent bacteria.

Step 3: In weeks, roots develop. Pot up once well-rooted.

Step 4: Plant in light, porous, moisture-retentive mix. Handle delicate roots carefully.

Winter Garden Cleanup

After saving annuals and storing bulbs, shred fallen leaves for compost or till into soil for winter decay. Remove dead plants, shake off soil, compost them. Tackle late weeds. Rake soil smooth, neaten edges. Clean tools, wind twine, wash gloves, coil hoses, collect labels. Then enjoy tea and seed catalogs—next year awaits!