Geranium in Zone 3A — Mountain West

Geraniums bring a burst of color and fragrance to our short Mountain growing season, thriving in the intense sunlight and cool nights that give them a unique vibrancy. Their versatility extends beyond the garden, with uses in everything from attracting pollinators to edible and medicinal uses. The satisfaction of nurturing these beauties in our challenging climate makes it all worthwhile.

While our high altitude and short growing season present unique challenges for Geraniums, careful timing and a few regional-specific strategies will help you enjoy these flowers. With a growing season that can be as short as 96 days, starting early and providing adequate protection are key to success.

Starting Geraniums from seed indoors is an option, but be aware that they're notoriously slow to get going. If you're up for the challenge, starting seeds indoors from mid-March through early April gives them a good head start, about 12 weeks before you can safely transplant them outdoors.

Use seed trays with a good quality seed-starting mix. Consistent warmth (around 70-75°F) is important for germination, so a heat mat can be helpful. Once seedlings emerge, provide plenty of light – a grow light works best, given our late spring and often cloudy conditions. Bottom watering helps prevent damping-off and encourages strong root growth.

Keep in mind that our late springs in the Mountain West mean you need to be patient. Geraniums take their time, so buying established starts from a local nursery is often the easier route to a colorful garden.

Transplant your Geraniums outdoors from mid- to late June, after all danger of frost has passed. Before transplanting, harden them off by gradually exposing them to outdoor conditions for about a week. Start with an hour or two of shade, increasing the time and sun exposure each day.

Space Geraniums 10-12 inches apart to allow for good air circulation, which is important in our climate to prevent fungal diseases. Even in June, we can still get unexpected cold snaps, so be prepared to cover your transplants if frost threatens. Because they're slow from seed, most Mountain gardeners find that buying starts is the easiest way to guarantee blooms in our short season.

Geraniums need moderate watering, but they definitely don't like soggy soil. In our dry Mountain climate, the key is to find the right balance. During the hottest part of the summer (if we even get a "hottest part," right?), you'll likely need to water them about twice a week.

Use the "finger test" – stick your finger about 2 inches deep into the soil. If it feels dry, it's time to water. Aim for about an inch of water per week, either from rainfall or supplemental watering. Watering at the base of the plant is best to avoid wetting the foliage, which can lead to problems in our high-altitude gardens.

Signs of underwatering include wilting leaves and dry, crispy edges. Overwatering, on the other hand, can cause yellowing leaves and stem rot. A light layer of mulch, like pine needles or shredded bark, helps retain moisture in the soil and regulates soil temperature, which is beneficial in our variable climate.

Regular pruning, or deadheading, will keep your Geraniums blooming throughout our short season. The goal is to encourage new growth and prevent the plant from putting energy into seed production.

Simply pinch or cut off spent flower clusters just below the flower head. This encourages the plant to produce more blooms. Throughout the summer, pinch back any leggy stems to encourage bushier growth and a more compact shape. As our first frost approaches in early September, stop deadheading to allow the plant to harden off and prepare for the end of the season.

While you won't be "harvesting" Geraniums in the traditional sense, you'll be enjoying their beauty from late August through early September, depending on when you transplanted them. The "harvest" is really the continuous enjoyment of their blooms.

As flowers fade, remove them promptly to keep the plant looking tidy and encourage more blooms. To "harvest" a few blooms for arrangements, cut the stems cleanly with sharp scissors or pruners. As the first frost approaches in early September, consider bringing potted Geraniums indoors to extend their bloom time.

Here are a few common problems to watch out for with Geraniums in the Mountain West:

Botrytis Blight

• What it looks like: Gray mold on flowers, leaves, and stems, often starting as small, water-soaked spots.
• What causes it: High humidity and poor air circulation. While we have low humidity, overcrowding plants can create pockets of moisture.
• How to fix/prevent it: Provide good air circulation by spacing plants properly. Remove infected plant parts immediately. Avoid overhead watering, especially in the evening.

Geranium Budworm

• What it looks like: Holes in buds and flowers, often with small, green caterpillars inside.
• What causes it: Moths lay eggs on the plant, and the larvae (budworms) feed on the buds and flowers.
• How to fix/prevent it: Inspect plants regularly for caterpillars. Handpick them off and destroy them. Use insecticidal soap or *Bacillus thuringiensis* (Bt) if infestation is severe.

Edema

• What it looks like: Small, blister-like bumps on the undersides of leaves, which can turn brown and corky.
• What causes it: Inconsistent watering and cool, damp conditions. The plant takes up water faster than it can transpire, causing cells to burst.
• How to fix/prevent it: Ensure consistent watering and good drainage. Improve air circulation around the plants. Avoid overwatering, especially during cool periods.

Mountain West Specific Challenges: Our intense sun can scorch Geranium leaves if they're not properly acclimated. Make sure to gradually introduce new plants to full sun. Alkaline soil can also be a problem, so amend your soil with compost to improve drainage and lower the pH slightly.

Geraniums make good companions for several plants in the Mountain West garden:

• Tomatoes and Peppers: Geraniums are said to repel certain pests that bother tomatoes and peppers, like aphids and whiteflies.
• Corn: The strong scent of Geraniums can deter some corn earworm moths from laying eggs on your corn.
• Roses: Geraniums can help deter Japanese beetles, which can be a major problem for roses in some areas.

Avoid planting Geraniums near plants that prefer very dry conditions, as their moderate watering needs might be too much for drought-tolerant species.