Sub-Zero Roses
The Brownell Sub-Zero rose series is a lovely collection of hardy hybrid tea roses. This group of tea roses tends to grow somewhat tall and often blooms in clusters, which is a trait more standard to floribunda roses.
Many retailers claim they are hardy to zone 3, however they are not. The Sub-Zeros have been found to be completely hardy to 15-20 degrees below farenheit, so most gardeners would agree that in zones 5 and colder they will need winter protection. That is still a very hardy tea rose, just beware of the hardiness claims. More specific information for each rose is below.
They do seem to all be grafted to hardy root stock. This is what makes the rose marginally hardy in zones 4 and 5. Absolutely plant them deep (the bud union several inches below the soil surface), and mound soil well up over the graft and crown for winter protection. Zone 5 gardeners might also consider at least minimal protection for winter.
Sub-Zero ‘Arctic Flame’
- Class: Hybrid tea
- Sun: Full sun, may tolerate partial shade
- Height: 3-4’
- Spread: 2-4’
- Growth Habit: Upright and bushy
- Bloom Color: Rich red
- Flower Form: Classic double hybrid tea
- Flower Size: Large, 4-6”
- Petal Count: 55
- Bloom Season: Repeating, early spring to frost
- Fragrance: Moderate to strong fragrance
- Stem: Thorned
- Foliage: Deep emerald
- Disease Resistance: Excellent disease and insect resistance
- Soil: Prefers enriched well drained
- Hardiness: zones 5-10, to -15 degrees F without protection
‘Arctic Flame’ has rich red blooms that don’t fade as they mature. It is a reliable bloomer producing up to 100 blooms on long stems. Blooming occurs in flushes throughout the season. ‘Arctic Flame’ grows quickly and vigorously, and once established is fairly resistant to drought periods. It holds up to summer heat well. This is a vigorous and long lived rose. Sub Zero roses are hardy to 15-20 below Farenheit without protection, and to 30-25 below Farenheit with minimal to moderate protection. In zone 5, Sub-Zero roses may require minimal winter protection. In zone 4, Sub-Zero roses may require moderate winter protection. In zone 3, Sub-Zero roses may require moderate to maximum winter protection. Prune following instructions for hybrid tea roses.
Sub-Zero ‘Charlotte Brownell’
- Class: Hybrid tea
- Sun: Full sun
- Height: 3-4’
- Spread: 2-3’
- Growth Habit: Upright
- Bloom Color: Yellow with edges blushed pink
- Flower Form: Classic double hybrid tea
- Flower Size: Large, 4-6”
- Petal Count: 50
- Bloom Season: Repeating, from late spring to frost
- Fragrance: Strong fragrance
- Stem: Thorned
- Foliage: Glossy green
- Disease Resistance: Excellent disease resistance
- Soil: Prefers enriched well drained
- Hardiness: zones 4b-9, to -30 degrees F without protection
‘Charlotte Brownell’ blooms in flushes throughout the season. Sub Zero roses are hardy to 15-20 below Farenheit without protection, and to 30-25 below Farenheit with minimal to moderate protection. In zone 5, Sub-Zero roses may require minimal winter protection. In zone 4, Sub-Zero roses may require moderate winter protection. In zone 3, Sub-Zero roses may require moderate to maximum winter protection. Prune following instructions for hybrid tea roses.
Sub-Zero ‘Curly Pink’
- Class: Hybrid tea
- Sun: Full sun
- Height: 3-4’
- Spread: 2-3’
- Growth Habit: Upright
- Bloom Color: Medium pink
- Flower Form: Classic double hybrid tea
- Flower Size: Large, 4-6”
- Petal Count: 50
- Bloom Season: Repeating
- Fragrance: Strong fragrance
- Stem: Thorned
- Foliage: Glossy green
- Disease Resistance:
- Soil: Prefers enriched well drained
- Hardiness: zones 6-10
Each stem of ‘Curly Pink’ produces several beautiful pink blooms with curly petals. It is very free flowering. Sub Zero roses are hardy to 15-20 below Farenheit without protection, and to 30-25 below Farenheit with minimal to moderate protection. In zone 5, Sub-Zero roses may require minimal winter protection. In zone 4, Sub-Zero roses may require moderate winter protection. In zone 3, Sub-Zero roses may require moderate to maximum winter protection. Prune following instructions for hybrid tea roses.
Sub-Zero ‘Dr. Brownell
- Class: Hybrid tea
- Sun: Full sun
- Height: 3-4’
- Spread: 2-3’
- Growth Habit: Upright
- Bloom Color: Yellow blend
- Flower Form: Classic double hybrid tea
- Flower Size: Large, 5-6”
- Petal Count: 34
- Bloom Season: Repeating, in flushes spring to frost
- Fragrance: Strongly intense fragrance
- Stem: Thorned
- Foliage: Glossy dark green
- Disease Resistance: Excellent disease resistance
- Soil: Prefers enriched well drained
- Hardiness: zones 5b-9b, to -20 degrees F without protection
‘Dr. Brownell’ produces large tea rose blooms beautifully blended with buff, yellow and apricot. The elegant buds are long pointed. Sub Zero roses are hardy to 15-20 below Farenheit without protection, and to 30-25 below Farenheit with minimal to moderate protection. In zone 5, Sub-Zero roses may require minimal winter protection. In zone 4, Sub-Zero roses may require moderate winter protection. In zone 3, Sub-Zero roses may require moderate to maximum winter protection. Prune following instructions for hybrid tea roses.
Sub-Zero ‘Helen Hayes’
- Class: Hybrid tea
- Sun: Full sun
- Height: 3-4’
- Spread: 2-3’
- Growth Habit: Upright
- Bloom Color: Yellow blend
- Flower Form: Classic double hybrid tea
- Flower Size: Large, 4-5”
- Petal Count: 43
- Bloom Season: Repeating, from spring to frost
- Fragrance: Moderate fragrance
- Stem: Nearly thornless
- Foliage: Glossy green
- Disease Resistance: Susceptible to mildew.
- Soil: Prefers enriched well drained
- Hardiness: zones 5b-10b, to -20 degrees F without protection
‘Helen Hayes’ is a very heavy bloomer, producing uniquely blended petals of yellow tinged with pink and deepening to an apricot orange. The bush is very vigorous and hardy. Sub Zero roses are hardy to 15-20 below Farenheit without protection, and to 30-25 below Farenheit with minimal to moderate protection. In zone 5, Sub-Zero roses may require minimal winter protection. In zone 4, Sub-Zero roses may require moderate winter protection. In zone 3, Sub-Zero roses may require moderate to maximum winter protection. Prune following instructions for hybrid tea roses.
Sub-Zero ‘Senior Prom’
- Class: Hybrid tea
- Sun: Full sun
- Height: 3-4’
- Spread: 3’
- Growth Habit: Upright
- Bloom Color: Deep pink
- Flower Form: Classic double hybrid tea
- Flower Size: Large, 4-5”
- Petal Count: 38
- Bloom Season: Repeating, in flushes throughout the season
- Fragrance: Moderately sweet fragrance
- Stem: Thorned
- Foliage: Glossy dark green
- Disease Resistance: Excellent disease resistance
- Soil: Prefers enriched well drained
- Hardiness: zones 6-9
‘Senior Prom’ is a reliable bloomer producing bright pink classic blooms singly or in clusters. Sub Zero roses are hardy to 15-20 below Farenheit without protection, and to 30-25 below Farenheit with minimal to moderate protection. In zone 5, Sub-Zero roses may require minimal winter protection. In zone 4, Sub-Zero roses may require moderate winter protection. In zone 3, Sub-Zero roses may require moderate to maximum winter protection. Prune following instructions for hybrid tea roses.