Definitions Flashcards
Hardiness
Hardiness
Hardiness ratings
All ratings refer to the UK growing conditions unless otherwise stated. Minimum temperature ranges (in degrees C) are shown in brackets
H1a: under glass all year (>15C)
H1b: can be grown outside in the summer (10 - 15)
H1c: can be grown outside in the summer (5 - 10)
H2: tolerant of low temperatures, but not surviving being frozen (1 to 5)
H3: hardy in coastal and relatively mild parts of the UK (-5 to 1)
H4: hardy through most of the UK (-10 to -5)
H5: hardy in most places throughout the UK even in severe winters (-15 to -10)
H6: hardy in all of UK and northern Europe (-20 to -15)
H7: hardy in the severest European continental climates (< -20)
H6
Cultivar
Literally meaning cultivated variety, cultivar names are given to denote variation within species and that generated by hybridisation, in cultivation. To make them easily distinguishable from botanical names, they are not printed in italics and are enclosed in single quotation marks
Herbaceous perennial
Herbaceous means that the plant has non-woody stems that reach their full height and produce flower within one year, before dying back over the winter and then reappearing the following spring ready for a repeat performance. The term perennial essentially means that the plant will live for more than two years.
The term ‘perennial’ is used loosely by gardeners to indicate those plants which grow in beds & borders which are not trees, shrubs or bulbs. They are the ‘summer colour’ the ‘border flowers’ or make up a ‘flower garden’
Perennials - this term is used by gardeners for all non woody perennial plants including herbaceous perennials. It includes those which are evergreen or semi - evergreen such as
Bergenia ( elephants ears)
Epimedium
hellebore
Stipa gigantea (ornamental grass)
Herbaceous perennials differ in that all the stems die back in late autumn & early winter. The roots then survive below ground during winter, shooting again in spring. Well known examples include :
Delphinium
Geranium
Miscanthus ( ornamental grass)
Sedum
Short lived perennials may only live a few years but other perennials usually live for many years.
Foliage may be evergreen or die back in winter.
It should be noted that gardeners usually exclude woody plants (trees, shrubs & sub-shrubs) when talking about perennials however botanically ‘perennial’ just means plants that live for many years so can be applied to woody ones too.
They are kept alive through winter by means of a perennating roots system and resting buds at soil level.
They provide seasonal change in the garden
Two main uses for herbaceous perennials in a garden :
Mixed borders -
Used along with bulbs, annuals, biennials, ornamental grasses, trees & shrubs to create a display - most common use in a garden.
Herbaceous borders - herbaceous perennials grouped together for maximum summer impact. Now rare as smaller gardens need borders to have interest throughout the year.
Rhizomatous
Rhizomes expand horizontally, developing new root systems and sprouting new shoots from nodes (the area of the stem where buds form). Examples of rhizomatous plants that propagate through vegetative reproduction include lily of the valley, canna lily, ginger, and asparagus
Dioecious
having male reproductive organs in one individual and female in another. : having staminate and pistillate flowers borne on different individuals.
Biennials
any herbaceous flowering plant that completes its life cycle in two growing seasons. During the first growing season, biennials produce roots, stems, and leaves. During the second growing season, they produce flowers, fruits, and seeds, and then they die
Annuals
Plants that perform their entire life cycle from seed to flower. Annual Plains Coreopsis. to seed within a single growing season. All roots, stems and leaves of the plant die annually. Only the dormant seed bridges the gap between one generation and the next.
Stoloniferous
A horizontal stem that is located above the ground and usually produces adventitious roots and vertical stems at the nodes. Stoloniferous refers to a plant that bears stolons.
Stolon
In botany a stolon—also called a runner—is a slender stem that grows horizontally along the ground, giving rise to roots and aerial (vertical) branches at specialized points called nodes
Adventitious roots
Adventitious roots are plant roots that form from any nonroot tissue and are produced both during normal development (crown roots on cereals and nodal roots on strawberry [Fragaria spp.]) and in response to stress conditions, such as flooding, nutrient deprivation, and wounding.
Evergreen
In botany, an evergreen is a plant which has foliage that remains green and functional through more than one growing season. This also pertains to plants that retain their foliage only in warm climates, and contrasts with deciduous plants, which completely lose their foliage during the winter or dry season.
evergreen, any plant that retains its leaves through the year and into the following growing season. Many tropical species of broad-leaved flowering plants are evergreen, but in cold-temperate and Arctic areas the evergreens commonly are cone-bearing shrubs or trees (conifers), such as pines and firs.
Deciduous
(of a tree or shrub) shedding its leaves annually.
Bedding
Description
In horticulture, bedding is temporary planting of fast-growing plants into flower beds to create colourful displays, during spring, summer or winter. Plants used for bedding are generally annuals, biennials or tender perennials; succulents are gaining in popularity.
F1 Hybrid
A first generation plant arising from two distinct pure bred parents.
Often bred for one of the following:
- uniform appearance
- larger yield
- disease resistance
- larger flowers
- uniform ripening
F1 Hybrids are largely annual flowers & vegetable cultivars
They’re produced by controlling how plants interbreed or ‘cross’ .
By crossing 2 pure bred parents that have each been inbred for a particular desirable feature they produce a plant that has the best features of both.
Because the two parents (of the same species) are so different in genotype from each other, hybrid vigour results (the opposite of inbreeding)
Offspring are uniform and grow at the same rate, have the same growth habit, colour is the same, they flower at the same time, crop at the same time, and may be resistant to particular pests & diseases. These characteristics are essential for formal bedding displays.
This is significant for :
- germination (all at the same time)
- ease, reliance & consistency of harvests (eg F1 hybrid Brussels sprouts that ripen all the way up the st at the same time)
- more disease resilient displays
- increased harvests & therefor greater profits
- consistent appearance in product e.g. bedding plants for sale all same height and colour
Limitations:
- very expensive to produce
- seed collection is not true to type - F/ generations
Hybrid vigour
The quality of many hybrids that causes them to grow bigger, produce more flowers or fruit or increase disease resistance than their parents. Hybrid vigour declines with each generation so the original cross must be made each year.
