The ornamental sweet pea (Lathyrus odoratus), which is brightly colored and smells nice, is a favorite plant for casual cottage gardens and is easy to grow. Native to the Mediterranean, these plants do best in full sun and moist, rich, slightly alkaline soil during the growing season. For flowering, bone or blood meal amendments are often helpful. Most of the time, you can see these plants climbing up fences or trellises or spilling over the sides of pots. Despite having “pea” in their name, they are not edible and are toxic to humans and pets.
Sweet peas are a beloved garden flower known for their vibrant colors, sweet fragrance, and climbing growth habit But just how big do these plants get? In this article, we’ll take a look at the size range of sweet peas to help you determine if they are a good fit for your garden.
Typical Height
The typical mature height of most sweet pea varieties falls between 1-2 meters (3-6.5 feet) when provided with adequate structural support to climb. However through selective breeding there is quite a bit of variation in sweet pea heights. Here’s an overview
- Standard sweet peas: 1-2m (3-6.5ft)
- Dwarf/bush sweet peas: Up to 45cm (18in)
- Tall/climbing sweet peas: Over 2m (6.5ft)
So in general, most standard sweet peas will reach between 3-6.5 feet tall when mature and properly supported. Dwarf varieties max out around 18 inches, while vigorous climbers can be over 6.5 feet tall.
Growth Habit
In addition to height, sweet pea growth habits can differ. Here are the main types:
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Climbing – These sweet peas use tendrils to grab onto trellises, fences, or other structures. Climbing vines are the most common type and produce long stems ideal for cut flowers. They must be grown vertically.
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Bush – Bush sweet peas have a more compact upright growth habit. They do not produce long vining stems, and tend to be smaller plants overall. Bush peas are grown freestanding without any vertical support.
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Semi-dwarf – Semi-dwarf sweet peas fall in the middle. They may produce some vines and tendrils to grab onto minimal supports, but don’t require large vertical structures. Their height ranges from 60-90cm (2-3ft).
So when choosing sweet pea varieties, consider their mature height but also their growth habit. Climbers will sprawl unless given adequate trellising or fencing. Bush types work well in pots and small garden spaces.
Factors Affecting Size
Several factors influence just how large sweet peas will grow:
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Genetics – Some sweet pea varieties are genetically predisposed to be larger or smaller. Choose cultivars suited to your available space.
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Environment – Sweet peas grow larger in ideal conditions with full sun, fertile soil, and adequate water. Suboptimal environments result in smaller plants.
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Support – Climbing sweet peas reach their full potential size only when grown vertically on trellises or other structures up to 6 feet tall or more.
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Pruning – Regularly pinching out the tips of vines encourages bushier, more compact plants. Leave vines unpruned for taller plants.
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Container vs. ground – Sweet peas grown in the ground can develop larger, more sprawling root systems and grow bigger than plants in containers.
So in the right environment with proper support, sweet peas grow to be impressive 1-2 meter vines covered in flowers. But other situations produce more petite plants. Know your site conditions and provide adequate structural support for vigorous climbing vines. Bush types are better suited to small spaces and containers. With hundreds of sweet pea varieties to choose from, you can find a size perfect for your garden!
What Do Sweet Pea Flowers Look and Smell Like?
They have lots of flower clusters in the spring and early summer, in colors like red, pink, blue, white, and lavender. Sweet pea flowers resemble fringed butterflies, while their sturdy stems appear folded. Their fragrance is sweet, like a blend of honey and orange blossoms.
Propagating Sweet Pea
Sweet peas grow best from seeds, but if you don’t have any seeds and still want to make more plants, you can use seedling cuttings. The cuttings will catch up to soil-grown plants if taken in the early spring.
- You will need a jar of water, scissors, a healthy piece of seedling, and root hormone, if you want to use it.
- Take a healthy seedling stem and cut it into a 5- to 6-inch piece, just above a pair of leaves. Leave at least a few nodes open so that new growth can start.
- You can give rooting hormone if you want to encourage healthier, stronger rooting. Take the cut end of the stem and dip it into the hormone for five seconds. Then put the cut end in the water and put it somewhere that gets indirect sunlight.
- It takes about 7 to 14 days for roots to appear, after which you can plant each rooted stem cutting in soil. Giving the plant a greenhouse-like environment is best. For example, you could put a plastic bag over the cutting and leave it there. Give it about an hour of fresh air daily. It may take up to six weeks, but once you see new, strong growth, you can move it outside into the ground or a bigger pot.
How to grow sweet peas: tips from a sweet pea flower farmer
FAQ
How big is a sweet pea vegetable?
How big does sweet pea grow?
Does sweet pea come back every year?
How tall of a trellis for sweet peas?
What is a sweet pea?
Sweet pea (Lathyrus odoratus) is a climbing, flowering, sweet-smelling annual in the legume genus. Originating in the southwest of Italy and the islands of the Mediterranean, sweet pea has been used in gardens since the 17th century. Sweet peas lend a cottage feel to gardens.
How tall does a sweet pea grow?
It is an annual climbing plant, growing to a height of 1–2 metres (3 ft 3 in – 6 ft 7 in), where suitable support is available. The leaves are pinnate with two leaflets and a terminal tendril, which twines around supporting plants and structures, helping the sweet pea to climb.
What does a sweet pea plant look like?
The leaves are pinnate with two leaflets and a terminal tendril, which twines around supporting plants and structures, helping the sweet pea to climb. In the wild plant the flowers are purple, 2–3.5 cm (3⁄4 – 1+1⁄2 in) broad; they are larger and highly variable in color in the many cultivars. Flowers are usually strongly scented.
How long does it take sweet peas to grow?
Use a heat mat set at 70 degrees F. The shoots should take root in 2 to 3 weeks. You cannot root cuttings from older shoots, so it is important to take cuttings from young, fresh growth (The Sweet Pea Book by Graham Rice). Plant sweet peas 4 to 6 inches apart. After hardening off for 1 to 2 weeks, it’s time to transplant seedlings.
Are sweet peas Hardy?
Despite their delicate look, sweet peas are quite hardy. In USDA Hardiness Zone 7 or colder, plant them in very late winter or early spring as soon as the soil is dry enough to work.
How big does a pea tree grow?
Most varieties grow between three and seven feet as a vine if supports such as trellises, arbors, fences, or walls are available. The annual species, L. odoratus, may be confused with the everlasting pea, L. latifolius, which is a perennial.