Utah’s high desert climate demands patience for nasturtium, with planting best reserved for after the soil warms and the risk of a late freeze passes. Knowing the best time to plant nasturtium in utah can mean the difference between a vibrant, cascading display and a sad, frost-bitten patch. You want those bright blooms and peppery leaves, but timing is everything in the Beehive State.
Nasturtiums are tough, but they hate cold feet. If you plant too early, the seeds rot. Too late, and you miss the peak growing season. This guide walks you through the exact window, step by step, so you get it right.
Best Time To Plant Nasturtium In Utah
The sweet spot for planting nasturtium seeds in Utah is between mid-April and late May, depending on your elevation. For most of the Wasatch Front, aim for the last week of April to the first week of May. In higher elevations like Park City or Heber Valley, wait until late May or even early June.
Why this window? Soil temperatures need to be consistently above 55°F (13°C). Nasturtiums are frost-sensitive. A late freeze in early May can kill young seedlings. You must watch the weather, not just the calendar.
Understanding Utah’s Frost Dates
Utah’s last spring frost date varies widely. In Salt Lake City, it’s typically around April 20. In St. George, it can be as early as March 15. In Logan, it may be May 10. Check your local extension service for exact dates.
Your soil temperature matters more than the air temperature. Use a soil thermometer. Stick it two inches deep. If it reads below 55°F, wait. Patience pays off.
Elevation Matters
Utah ranges from 2,000 feet in the southwest to over 8,000 feet in the mountains. For every 1,000 feet of elevation gain, the growing season shortens by about a week. Adjust your planting window accordingly.
- Low desert (St. George area): Plant in March to early April.
- Valley floors (Salt Lake, Provo): Plant mid-April to mid-May.
- High valleys (Park City, Heber): Plant late May to early June.
- Mountain areas (above 7,000 ft): Plant in June, but expect a short season.
Soil Preparation For Nasturtiums
Nasturtiums prefer poor to average soil. Too much fertilizer, especially nitrogen, gives you lots of leaves but few flowers. They thrive in lean, well-drained soil. If your soil is heavy clay, amend it with sand or compost to improve drainage.
Test your soil pH. Nasturtiums like slightly acidic to neutral soil, around 6.0 to 7.5. Utah soil is often alkaline. If your pH is above 7.5, consider adding sulfur or planting in containers.
Preparing The Planting Site
- Choose a spot with full sun to partial shade. In Utah’s intense summer heat, afternoon shade helps.
- Loosen the soil to about 6 inches deep. Remove rocks and weeds.
- Mix in a thin layer of compost if needed. Avoid rich soil.
- Rake the surface smooth. Water it lightly before planting.
How To Plant Nasturtium Seeds
Nasturtium seeds are large and easy to handle. They have a hard outer coat. Soaking them overnight in warm water can speed up germination. Some gardeners nick the seed coat with a file, but this isn’t necessary if soil is warm.
Plant seeds about 1 inch deep. Space them 10 to 12 inches apart for bush varieties, or 18 to 24 inches for trailing types. Water gently after planting. Keep the soil moist but not soggy until seedlings emerge, which takes 7 to 14 days.
Direct Sowing Vs. Transplanting
Nasturtiums dislike root disturbance. Direct sowing is best. If you must start indoors, use peat pots or biodegradable containers. Plant seeds 4 to 6 weeks before your last frost date. Harden off seedlings slowly before moving them outside.
Transplanting shock can stunt growth. If you buy nursery starts, handle them carefully. Plant them at the same depth they were in the pot. Water well after transplanting.
Spacing For Different Varieties
- Dwarf bush types: 8 to 10 inches apart.
- Trailing or climbing types: 12 to 18 inches apart.
- Hanging baskets: 2 to 3 seeds per 10-inch basket.
- Ground cover: Space 12 inches apart for quick coverage.
Caring For Nasturtiums In Utah
Once established, nasturtiums are low-maintenance. They need little water. In Utah’s dry climate, water deeply once a week, or more often in sandy soil. Overwatering leads to root rot and fewer blooms.
Deadhead spent flowers to encourage more blooms. But if you want seeds, leave some flowers to dry. Nasturtiums self-seed readily. You might get volunteers next year.
Common Pests And Problems
Aphids love nasturtiums. In fact, nasturtiums are often used as trap crops to draw aphids away from other plants. If aphids appear, spray them off with a strong stream of water. Or use insecticidal soap.
Slugs and snails can be a problem in wet springs. Use diatomaceous earth or beer traps. Keep the area clean of debris.
Fertilizing Tips
Do not fertilize nasturtiums heavily. A light application of balanced fertilizer at planting time is enough. If you see yellow leaves, it might be a sign of overwatering, not hunger. In Utah’s alkaline soil, yellow leaves can also indicate iron deficiency. A foliar spray of chelated iron can help.
Harvesting And Using Nasturtiums
Both leaves and flowers are edible. They have a peppery, radish-like flavor. Harvest leaves when they are young and tender. Flowers are best picked just after they open. Use them in salads, as garnishes, or stuffed with cheese.
Seeds can be pickled as a substitute for capers. Harvest green seeds after the flower drops. Soak them in brine for a few days, then pack in vinegar.
Extending The Bloom Season
Nasturtiums bloom from summer until the first fall frost. In Utah, that can be as late as October in lower elevations. To extend bloom time, keep plants well-watered during heat waves. Mulch around the roots to keep soil cool.
If you want flowers into fall, plant a second batch in late June. This gives you fresh plants when the first ones start to fade. Succession planting works well for continuous blooms.
Overwintering Nasturtiums
Nasturtiums are annuals in Utah. They won’t survive winter outdoors. But you can collect seeds for next year. Let some flowers go to seed. When the seeds are brown and dry, collect them. Store in a cool, dry place.
If you have a sunny indoor spot, you can try growing nasturtiums as houseplants. They need bright light and cool temperatures. They might not bloom as profusely indoors.
Frequently Asked Questions
Can I Plant Nasturtium Seeds In July In Utah?
Yes, but the growing season will be shorter. In low elevations, July planting can still yield flowers before frost. In high elevations, it’s risky. You might only get leaves, not blooms.
What Happens If I Plant Nasturtiums Too Early?
Seeds rot in cold, wet soil. Seedlings can be killed by a late freeze. You waste time and seeds. Wait until soil is warm.
Do Nasturtiums Need Full Sun In Utah?
They prefer full sun but appreciate afternoon shade in Utah’s hot summers. Too much shade reduces blooming. Aim for at least 6 hours of sun daily.
How Deep Should I Plant Nasturtium Seeds?
Plant seeds about 1 inch deep. Cover lightly with soil. Water gently. Deeper planting can prevent germination.
Can I Grow Nasturtiums In Containers In Utah?
Absolutely. Containers warm up faster than ground soil. Use well-draining potting mix. Water more often, as containers dry out quickly in Utah’s dry air.
Final Tips For Utah Gardeners
Nasturtiums are forgiving plants. Even if you miss the ideal window, they often still perform. The key is avoiding frost and cold soil. Watch your local weather, not just the calendar.
If you have a short growing season, choose early-blooming varieties. ‘Alaska’ and ‘Jewel Mix’ are reliable. For trailing types, ‘Empress of India’ and ‘Whirlybird’ do well in Utah.
Remember, nasturtiums are drought-tolerant once established. In Utah’s arid climate, this is a big plus. They need less water than many annuals. Perfect for water-wise gardens.
One more thing: nasturtiums attract beneficial insects like bees and hoverflies. They also repel some pests. Plant them near vegetables like tomatoes and cucumbers. They make great companion plants.
So, get your soil thermometer ready. Check your frost dates. And when the soil warms, sow those seeds. You’ll have a colorful, edible garden that thrives in Utah’s unique climate.
Happy planting, and enjoy those peppery blooms all summer long.