All the sweet pea varieties belong to the genus Lathyrus, this genera of plants can easily be found growing in the wild in many places. The cultivated sweet pea is developed from the L. odoratus species, however, many other annual species in this genera are also grown as garden plants. These include the L. clymenum, L. sativus and the L. tingitanus species to name a few.
These flowers are seen in the few sweet pea varieties or forms that were developed from the wild species and were grown before the rapid takeover by the 'Grandifloras' variety. These forms were fixed from the wild type and do not owe anything to the Grandifloras variety and are hence called 'originals' by gardeners.
This variety of sweet pea represents the first major improvements in the sweet pea strain. The development of varieties with larger flowers and an aesthetically improved placement of the petals on the stem, with standards borne at a greater vertical angle and with the wings held more evenly made for much better display plants. Compared to the wild or original sweet pea varieties, the Grandifloras usually have clearer colors on the petals and tend to bear more flowers on the stem. The original sweet pea plants were selections derived from the first sweet pea introduced in Sicily and do not match up to the grandifloras in any of the characters desired by gardeners and floral enthusiasts. In comparison to the wild sweet pea, the Grandifloras are more fragrant. Grandifloras were developed over a period of time by different persons; the variety was mainly developed by Henry Eckford in Britain; as well as by C. C. Morse Et Co. and W. Atlee Burpee in California. However, different breeders also raised their own varieties of Grandifloras, some of which have disappeared without a trace. The Grandifloras variety is again being introduced and worked on by groups such as Peter Grayson, E. W. King & Co. and Unwins Seeds, resulting in the development of many new varieties in the same style. However, the similarity of forms possessed by the old Grandifloras that are grown today to those grown a century ago is not certain and even the old style Grandifloras of today may differ greatly from the early Grandiflora lineage. However, some of these plants resemble the old type and some have disappeared only to be "re-discovered", sometimes as reversions in the Spencer types or in the many Grandifloras variety of sweet peas. If such plants have great similarity in flower color to the original varieties, they are often also more vigorous, and the flowers they bear may in fact be of larger size and have stems with more flowers on them. The old literature also shows that many of these Grandifloras variety of sweet pea were not fixed when initially released into the market as new types, for example, some accounts even list the names of the other varieties that were seen in the market as rogues arising within a particular variety of sweet pea. This sort of problem is also faced by other old-fashioned plants that have recently undergone a revival in popularity, the pinks and old primroses are an example. There is another surprising fact to consider, for example, in the early development of the Spencer's sweet pea, the release of one type which was the same color as an existing "Grandiflora" borrowed the 'Grandiflora's' name and was called the 'Flora Norton Spencer'. This is the reason that one must know the type of flower grown today might not be an exact match to one that was grown under the same name a century or two ago, this applies to sweet peas as it does to all other popular garden plants.
This term is applied as a synonym for the "Grandiflora" variety of sweet peas in some cases, but it is also used at times to include the 'Cupani' variety and the very first varieties of sweet peas that were grown before introduction of the "Grandiflora" line.
This type of sweet pea flower was among the first breakthroughs away from the "Grandifloras" flower variety and is considered to be the intermediate sweet pea flower variety, lying between the "Grandifloras" type and the "Spencer's" type; with respect to size of flower as well as degree of ruffling seen in the petals. However, this term was dropped as Charles Unwin went on to develop this new varieties into styles that were more like the "Countess Spencer" type. The ruffling and the wavy nature of the Unwins variety was significantly less than that seen in the Spencer sweet pea varieties. However, the main advantage of the Unwins type was that it bred largely true to type - this was the result of the extremely painstaking work of Charles Unwin in ensuring that none of his seeds contained forms that were off the desired characteristics. The same consistency of form in floral structure was soon evident in his range of varieties modeled after the Spencer type of sweet pea.
The majority of the sweet pea varieties grown right now are from this group of sweet peas. The Spencer variety was "discovered" by a number of people, with the introduction of the 'Countess Spencer' variety, by Silas Cole, a gardener at Althorp Hall, United Kingdom, causing the biggest stir. The significantly larger flowers of the Spencer variety differentiate them from the earlier Grandifloras - the petals are also more noticeably ruffled and waved in the Spencers. Some varieties of Spencers also normally need twelve hour days to bloom; this character is shared with the Cuthbertsons and Winter-Flowering types of sweet peas introduced later. The name "Late Spencers" is given to these late blooming sweet pea types.
This variety of sweet pea was originally bred in California under the aegis of the Ferry-Morse Seed Company; the base of this variety is the Spencer's hybridized with an early-flowering American strain of sweet pea. The Cuthbertson variety of sweet pea is an early flowering type and blooms two weeks before the Spencer type, when grown in places with eleven hour days. This variety of sweet pea is also much better at withstanding the high summer temperatures in places where summers can get really hot. This variety is sometimes grown under glass to produce marketable cut flowers; each plant will bear four to six flowers per stem. However, the color range is quite limited and the flower form is overall less impressive than the Spencer's variety of sweet pea. As most available stocks of this variety of sweet pea have deteriorated in recent years, most growers have found that their Cuthbertsons do not actually flower much earlier than the Spencer's variety. These varieties are often called "Cuthbertson's Floribundas" for this reason.
This variety of sweet pea plants flowers at about the same time as the Spencer's variety of sweet pea. The 'Galaxy' sweet pea variety may bear up to eight, or more, flowers on a single stem but these flowers are almost always without the appearance of the ruffled petals typical of the Spencer form. The 'Galaxy' variety was touted to supersede the Spencers variety in the 1970s, however, this never happened and the Spencers variety continues to enjoy popularity.
These varieties are not marked by a sharp distinction; they are simply considered modern varieties of sweet pea, also referred as Semi-multifloras. These varieties typically bear five to seven flowers per stem, and the flowers are normally arranged in the waved Spencer form along the stem. The distinction is considered vague at best as most classic Spencers grown nowadays often boast of five flowers per stem.
This variety of sweet pea grows no taller than thirty cm or twelve inches in height. The dwarf sweet pea variety initially appeared suddenly as rogues in batches of other sweet pea varieties that were grown for seed. When the variety first appeared, it was white in color and was called the 'Cupid.' Soon other dwarf varieties were bred in other colors and were introduced but soon fell out of favor for decades and have only recently enjoyed a revival. The dwarf variety are all short plants and have very short stems, they are primarily of value as an annual ground cover. They are also perfect for growing in window boxes and in hanging baskets. A few dwarf sweet pea varieties are also scented. This sweet pea variety is once again being worked on by plant breeders and the 'Pink Cupid' type has become a well known and popular garden centre plant. There are other names for the sweet pea varieties found in this group, in addition to the 'Cupid Series', these include the 'Fantasia', the 'Patio', the 'Little Sweetheart', the 'Color Carpet', the 'Sweetie' and the 'Pinocchio' groups.
This variety of sweet pea was developed mainly in the USA through crosses involving the "Dwarf types" and the Spencer's variety. A well known intermediate type, the 'Bijou' can grows to about two feet or sixty cm tall, while the 'Knee-Hi', the 'Jet-Set' and the 'Continental' are a little taller at around three feet or ninety cm tall. The intermediate type is also sometimes known as the "Semi-dwarf" sweet pea variety. This category of plants includes the tendril-free variety, the 'Snoopea', as well as the 'Supersnoop', the 'Explorer' and the 'New Century Constellation' series. This variety is quite popular with many gardeners.
Early or Winter-Flowering
This variety of sweet pea develops and blooms rapidly, and needs just ten hours of daylight to bloom fully. The variety is meant for growing in areas where the summers are too hot for other types of sweet peas. The variety grows best before the heat turns extreme in the summer. The best example of this variety that is also widely grown is "The Winter Elegance" - quite popular with many gardeners.
Early Multiflora Giganteas
This variety of sweet pea was developed before the Spencer's variety and are quite popular with commercial cut flower growers, as they produce very large and good-quality flowers borne on long stems. The most popular one is "The Mammoth Series," which is marked by the longest stems, and a very large flower. This series is also known for great uniformity in the flowering time across different floral colors.
This variety of sweet pea bears unusual slender and acacia like foliage in place of the tendrils seen on other sweet pea varieties. The three most common Intermediate types are the Snoopea, the Supersnoop and the Explorer. These types together with the relatively new "New Century Constellation" series are quite popular with many floral enthusiasts. The absence of tendrils on the plant is less of a disadvantage to plant varieties that are short compared to the tall varieties of sweet pea - where tendrils are needed for support. However, tall tendril-free types of sweet peas have been introduced from time to time, but these never proved to be a great success due to the aforementioned problems. Thompson & Morgan have more recently introduced the tendril free 'Astronaut' mixture, that bears Spencer type flowers and this new introduction has seen some popularity.
The Royals are an improved form of the "Cuthbertsons" variety of sweet pea, these forms are also mixed from Ferry-Morse. The stems on these plants are lengthier and stronger than classical sweet pea varieties, the plants also tend to be more vigorous and the flowers they bear are larger. However, they are late in blooming compared to the types they are derived from. The great advantage is that the Royals are more tolerant of hot and bright summer weather than more popular "Spencer types" of sweet pea.
Types of flowers
Here the color of the flower produced is more or less uniform along the whole flower, having equal distribution of pigments on both the standards and the wings.
In this type of flower, the upper part of the flower or the standard, has a different color from the wings - sometimes it is a darker version of the same color observed on the wings. These flowers tend to be visually attractive, in fact, the sharper the distinction between the coloration of the wings and standard - the more effective and dramatic their overall appearance.
In this flower type, the standards on the flower are a paler shade than the coloration seen on the wings. The coloration on this type of flower is a simple reversal of the coloring pattern seen in the bicolor type of sweet pea flower.
This type of flower is marked by a boldly patterned coloration; both the standards and wings are streaked and usually, have a dark color on a white or grey white background color. The reverse coloration observed on both the standard and the wings are quite similar to the coloration seen in the front - however, they tend to be intensely colored; the sweet pea called 'America' is an early Grandiflora with this type of floral coloration.
This type of sweet pea flower is dramatically marked and the color is usually white, or a color which is almost white. This flower is also marked by a striking pattern. In these flowers, the standards are edged by a narrow band of color, while the rest usually remains colorless. There is heavy coloration on the reverse as well as a narrow colorless zone between the colored zone and the narrow colored rim. The coloration on the wings is quite similar to the coloration seen on the standard - however, it is reversed. The upper surface of the wings have intense coloration, with the presence of a narrow colorless zone immediately inside the colored wired rim; the coloration also persist on the edges facing each other over the keel. The undersides of the wings are more or less white in color, while the edges are wired in coloration. When the flower is observed, the heavy coloration on one side dulls the purity of the whiteness on the other side. A good example of this type of floral coloring is the 'Wiltshire Ripple'. The use of the terms 'stripe' and 'flake' was much less frequent than it is these days.
This form of flower is rare, here the veins of the petals are colored and marked off distinctly from the rest of the petal surface.
The flower types known as the picotees posses a narrow border along the edges of petals. This is in a darker shade and at times contrasts greatly to the color on the larger surface of the petal. A good example of this type of flower is the familiar 'Rosy Frills' sweet pea.