These standards apply only to cultivated turf produced by the members
of the Turfgrass Growers Association (TGA) and supplied with a
declaration that it meets set criteria. The intention is to set
a minimum standard for good quality cultivated turf for use in
general landscape situations.
Turf intended for some uses on
sports facilities demands a more rigorous standard, particularly
in relation to soil type, which this standard does not address.
Turf consisting predominantly of agricultural or wild grasses
cannot by definition meet the TGA quality standard.
The results of the following assessments, together with a
statement that turf has been grown from good quality turfgrass
cultivars on a suitable soil type are to be recorded on a
declaration form completed by the turf grower on the day of
lifting and made available to customers.
The dimensions of the turves in the consignment are to be
declared. The most common type of cultivated turf in the UK is
the roll, 1 square metre (406mm x 2465mm) or 1 square yard (16"
x 81") in area, and those parts meeting of a standard relating
to this manual. 'Big rolls' in a variety of dimensions (most
commonly 25 square yards in area) are increasingly popular for
large-scale landscape projects. Turf may also be supplied in
rectangular pieces of other sizes to be agreed with the customer
in advance. Deviation from the declared size shall be plus or
minus 15mm in width and plus or minus 5% in length.
The sward must be green and must not be visibly affected by any
pest or disease.
Suitable types of soil for turf production for landscape
purposes are peats, sands (including organic sand) and loams
containing less than 40% clay as determined by particle size
analysis. Turf grown on soil designated, as 'clay' is not
suitable for general landscape purposes.
Cultivars of turfgrass used for cultivated turf production
should be shown in the edition of 'Turfgrass Seed' *(1) current
in the year of sowing the crop and listed in the declaration.
The turf is to be composed of the sown turfgrasses which should
occupy at least 95% of each turf. Any other species present and
their approximate % cover are also to be listed in the
declaration.
The content of plants in the turf (grasses and broad-leaved
weeds) is to be objectively assessed with the appropriate
quadrats using the techniques described in 'Methods'. In the
first instance a rectangular quadrat, such as the standard TGA
75cm square may be used, but in the event of a dispute or for a
more accurate ground cover assessment the more precise "New
optical point quadrat" *(2) should be used. This is a more
accurate instrument for the assessment of ground cover in close
mown turf and the results of an assessment conducted as
described in the 'Methods' (section B.1.b) will be final.
1 Obtainable from The Sports Turf Research
Institute, Bingley, West Yorkshire BD16 1AU.
The height of the sward when harvested should not exceed 35mm as
measured using the technique described in the 'Methods' (section
B.2.i)
The thickness of uncompressed thatch should not exceed 10mm as
measured using the technique described in the 'Methods' (section
B.2.ii, a and b)
The soil layer beneath the thatch should be between 5 and 15mm
deep as measured using the technique described in 'Methods'
(section B.2.iii) and this thickness should be uniform within a
consignment of turf.
A declaration must be made as to whether sod netting is
incorporated in the turf. If it is present at point of sale it
should be embedded in the turf and must not project above the
thatch layer. (This statement does not apply to removable
netting wrapped around pallets or "big rolls" to protect the
harvested turf.)
To demonstrate strength, it should be possible to lift 1 sq.
metre or 1 sq. yard turves clear of the ground by their shortest
side. At least 15 out of 20 turves tested in this way should
remain intact.
Rolls of 1 square yard or 1 square metre in area must weigh less
that 20kg, unless the turf is very wet due to rain on the day of
harvest.
