The genus Rubus, (especially the blackberries, which are often loosely referred to as Rubus fruticosus agg.) presents some of the most difficult taxonomic problems. This is partly due to the frequency of polyploidy; also to the frequent occurrence of hybridization; and also due to apomixis, where minor differences between plants are preserved because seedlings are genetically identical to their parent. As a result, differences of opinion on the number of species to be recognized from a given region can vary tremendously (for example, a treatment by M. L. Fernald[] in 1950 recognized 205 species for the northern half of the eastern United States plus parts of southeastern Canada, whilst H. A. Gleason and A. Cronquist in 1991 recognized only 25)[]. Where possible, a relatively conservative approach is taken here[].

Common Name: Loganberry

General Information

Rubus loganobaccus is a deciduous shrub producing each year a cluster of vigorous, prickly, deciduous stems from a woody rootstock; the stems can be 250cm or more long, with some specimens scrambling up to 5 metres into supporting vegetation[]. The stems only produce leaves, and do not flower, in their first year of growth, forming flowering branches in their second year and then dying after fruiting.
The plant is often cultivated, especially on a garden scale, for its edible fruit.

Known Hazards

None known

Botanical References

,

Range

Probably a hybrid between Rubus ursinus and the raspberry 'Red Antwerp'.

Habitat

Not known in a truly wild situation.

Properties

Edibility Rating
Other Uses Rating
Habit	Deciduous Shrub
Height	2.50 m
Growth Rate	Fast
Pollinators	Apomictic
Self-fertile	Yes
Cultivation Status	Cultivated

Cultivation Details

Rubus loganobaccus is hardy to about -18°c[].
Easily grown in a good well-drained loamy soil in sun or semi-shade[, , ]. Tolerates all but the most alkaline soils[]. Plants dislike exposed windy situations[].
This species was first established in California in 1883, where it was found growing in the garden of J. Logan as an accidentally crossing of the octoploid blackberry species Rubus ursinus with a tetraploid cultivar of the raspberry (Rubus idaeus)[, ].
Often cultivated for its edible fruit in temperate countries, there are some named varieties[], including forms with thornless stems[, ]. 'LY654' is a thornless form with good flavour[].
The plant usually crops heavily[].
The plant produces apomictic flowers, these produce fruit and viable seed without fertilization, each seedling is a genetic copy of the parent[].
Plants in this genus are notably susceptible to honey fungus[].
Plants are liable to attacks of raspberry cane spot and mildew, otherwise they are one of the most reliable of the fruiting members of this genus[].

Edible Uses

Fruit - raw or cooked[, , , , ]. A pleasant acid flavour[]. The fruit is up to 40mm in diameter[].
These are eaten raw and processed for cans, jelly, jam or syrup[].

Medicinal

None known

Other Uses

A purple to dull blue dye is obtained from the fruit[].

Propagation

Seed - requires stratification and is best sown in early autumn in a cold frame. Stored seed requires one month stratification at about 3°c and is best sown as early as possible in the year. Prick out the seedlings when they are large enough to handle and grow on in a cold frame. Plant them out into their permanent positions in late spring of the following year.
Cuttings of half-ripe wood, mid summer in a frame[].
Tip layering in July. Plant out in autumn.
Division in early spring or just before leaf-fall in the autumn[].