Feb 18, 2014

Different forms of seed

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Native Seeds sells a range different grass types, but there are different ways that the seed is prepared for sale.

Seed is sold as:

• clean seed
• floretted seed
• pelletised seed
• seeds and awns (kangaroo grass)
• seed in thatch form
• summary.

The method used is usually the result of the different characteristics of the seed.

Australian native grass seeds have notbeen modified by years of selective breeding and usually come wrapped in fluffy appendages or with long awns or with awns that make them form asmall ball like steel wool.

So what are the advantages and limitations of these various seed forms?

Clean-SeedCleaned seeds

These are seeds that have been cleaned of their appendages to expose the caryopsis, or kernel of the seed. These seeds are easy to sow through conventional equipment as they flow easily and can be sown to the desired depth.

The disadvantage of using cleaned seed is that it is not able to bury itself, relies on human activity for dispersal and needs to be sown into the soil under controlled conditions. Sometimes these seeds will germinate faster than floretted seed, but this only occurs when conditions are ideal – the soil is well cultivated, the temperature is correct and there is a regular and constant moisture level.

Native Seeds sometimes prepares seed in the cleaned form for use by specific clients such as turf farms where conditions are guaranteed to be ideal, otherwise we usually recommend sowing seed in the floretted form or the pelletised form.

Floret-seedFloretted seed

This means seed that is still enclosed in its various appendages such as fluffy lemmas or glumes or even twisted awns. For some seeds such as wallaby grass, this means that it is very hairy and wide; for others such as spear grass it means long awns that twist and interlock; while for others like weeping grass this means interlocking awns. All of these appendages make these seeds impossible to sow through conventional equipment.

They do offer advantages for establishment in some conditions. Often the appendages help to disperse the seed, often they help to help bury the seed in the ground and in many cases the appendages help to hold moisture around the seeds which aids germination.

  Pelletised-seedPelletised Seed

Recent technological advances have seen the development of pelletising processes that wrap the entire floretted seed in a coating. This has dramatically improved the ability of the seed to be sown by conventional equipment as the seed, once pelletised, is able to flow freely. It also offers other potential advantages through the capacity to include other ingredients into the pelletising material. It is possible to add in some plant protection factors such as a fungicide for protection against seedling diseases, an insecticide for control of sucking pests in the early plant stages and even beneficial fungi to help to promote plant growth on difficult or sterile soils. It may even be possible to add small amounts of specific plant nutrients on soils that are known to be limited by the availability of the ingredient.

Seed pelletizing does add weight to each seed and hence there are fewer seeds per kilogram. But there are many compensating advantages through higher rates of seedling establishment. However, the sowing rate usually needs to be doubled for pelletised seed.

Native Seeds is continuing to investigate the use of seed pelletising for our native grasses and will incorporate new technologies once they have been proven to be advantageous to seedling establishment.

Kangaroo-seeds-lawnsSeeds and Awns

This form applies mainly to Kangaroo grass as it is a particularly difficult grass to clean down to cleanseed. We have been spending considerable time on our efforts to develop a successful cleaning method, developing new machinery in the process. At this stage, all our top end Kangaroo grass product is sold in this form. It consist of seed and awns with a small amount of mulched straw. It is easy to sow, as the seed will flow through commercial seeding equipment.

Kangaroo-floret Thatch form

 Kangaroo grass has been sold in the thatch form for some years and occasionally Native Seeds keeps a smallpart of its crop for cutting and sale in the thatch form. To produce thatched seed, the entire stem of the kangaroo grass plant is cut about 150mm (6 inches) off the ground and gathered together. Sometimes these stems are simply laid flat on the areas to be sown; while at other times they are stacked and stored prior to dispersal.

Kangaroo-clean The advantages of this process are that seed is not lost through the harvesting process and that there is an amount of mulch material available for protection of the prepared ground. There is also a potential gain from ongoing maturation of some partially ripe seeds while in the thatch, though this is somewhat unreliable.

The disadvantages are that the amount of seed included cannot be precisely known, the viability of the seed cannot be tested, the rate of spread of the seed cannot be controlledand the evenness of sowing is very poor.

Summary

Clients should contact Native Seeds to see what seed form is the most appropriate for the application.

Provenance

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When revegetation projects are undertaken, there is occasionally a demand for seed of local provenance, that is seed which has been gathered from the local area where revegetation is to occur. This is because the local trees and shrubs have adapted well to that environment and local material of these plants usually does perform better. Many people assume that the same rule will apply to grasses.

While local provenance is relevant for trees and shrubs, it is not relevant for revegetation using native grasses because of the way grasses reproduce. It is often assumed that cross pollination is the normal fertilisation for all plants, but this is not so for native grasses. While there is considerable variety in the way Australian native grasses flower and produce seed, all the grasses studied to date produce the majority of their seed by some form of self-pollination and not by cross pollination. Many grasses including Wallaby grass and Weeping grass are self fertilising and spikelets are fertilised before they emerge from the leaf sheath. Some grasses are able to produce fertile seed asexually. The grasses don’t display inbreeding characteristics because they have more than two basic sets of chromosomes. Kangaroo grass, for example, has from two to six sets of chromosomes and Weeping grass has four sets of chromosomes. Other grasses such as Redgrass and Bluegrass species have some flower spikelets with two sets of chromosomes, while others on the same plant may have many sets of chromosomes.

Thus there is genetic diversity within each plant rather than within different individuals within a population. So there can be distinct genetic variations within one species in the same paddock. It then becomes impossible to determine what is local.

Furthermore, distance is not a factor in determining genetic diversity for native grasses. Studies have shown that different types of Wallaby grass, Rytidosperma caespitosum, can be found with different characteristics within one to two kilometres. We know that in other areas variation is far less and the same type can extend to several hundred kilometres. Both wild species and bred cultivars of native grasses will grow well outside their normal range thus displaying broad scale adaptation.

Often too, there is a fear that by introducing new genotypes of species into an area that the local population of plants will be contaminated. As the native grasses are self fertilising, out-crossing is likely to be very infrequent with a minimal risk of contamination of other plants.

Long term studies over many years of native grasslands, have shown there are quite rapid changes in the dominant species in the grassland community. Thus the grasslands themselves are constantly changing in response to climate and other environmental factors. The introduction of native grass seeds from commercially available sources should improve genetic diversity and there should be no concerns about unwanted contamination of species through outcrossing as the grasses are self fertilising.

See Presentation by Dr. Wal Whalley

New Review article on Seed Supply for Restoration :Florabank article:

Sowing Notes: Summer lawn mix

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Sowing Notes: Summer lawn mix

– a blend of Wallaby Grass, Griffin Weeping Grass and Redgrass

A lawn made of a mixture of Weeping grass, Wallaby grass and Redgrass is fine textured, yet more hardy and drought tolerant than Griffin or Wallaby grass on its own.

Wallaby and Griffin Weeping grass are cool season perennial grasses while Redgrass is a summer growing perennial. All the grasses will grow on clay loam to light sandy soils. This grass blend has above average tolerance to high temperatures and will grow very successfully in shading situations. Griffin Weeping grass may brown off during summer, but greens up when moisture is available. Wallaby grass will usually stay green and the Redgrass will actively grow during the summer months.

During the cooler months, the Griffin and Wallaby grass will actively grow and the Redgrass will go dormant, taking on a slight reddish tinge in colour.

Sowing:

Native grasses do not like competition from weeds as they have relatively slow growth rates, so ensure the soil is well prepared and weed free prior to sowing.

Sow the seeds in spring or early autumn when the soil is moist for best results. The Redgrass will only germinate once air temperatures are above 25˚C. Sow the seed by distributing it evenly over the soil surface then lightly rake over to ensure that all seed is in good contact with the soil.

Keep the seed moist until the seedlings are established, but do not flood or waterlog the soil.

Germination should take place within 10 – 14 days for the Griffin Weeping grass, within 14 – 21 days for the Wallaby grass and approx. 7 – 10 days for the Redgrass.

Please be patient.

Wallaby grass seedlings are very small and fine when they emerge.

Weeping grass seedlings are wider and flatter than Wallaby grass.

At the early stages of establishment, keep broad leaved weeds under control by hand weeding.

Maintenance:

Allow the seedlings to thicken up before mowing.

Keep the mowing height above 40mm.

The lawn should only need infrequent mowing, possibly only 6 times per year.

A general lawn fertilizer can be applied at 3 months and then only occasionally, if at all.

Sowing Notes: Winter Lawn Mix

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Sowing Notes: Winter Lawn Mix

Winter Lawn Mix – a blend Wallaby Grass sp. and Griffin Weeping Grass.

A lawn made of a mixture of Weeping grass and Wallaby grass is fine textured, yet more hardy and drought tolerant than Weeping grass on its own.

Both Wallaby and Weeping grasses are cool season perennial grasses which grow naturally in the temperate areas of eastern and south western Australia. They grow on clay loam to light sandy soils. Both grasses have above average tolerance to high temperatures. Weeping grass will brown off during summer, but greens up when moisture is available. Wallaby grass will usually stay green. These grasses are tolerant of cold and frost and will grow in shady situations.

Sowing:

Native grasses do not like competition from weeds as they have relatively slow growth rates, so ensure the soil is well prepared and weed free prior to sowing.

Sow the seeds between autumn and spring when the soil is moist for best results. Sow the seed 10 – 15mm below the surface, or if spread over the soil surface, lightly rake over to ensure that all seed is in good contact with the soil.

Keep the seed moist until the seedlings are established, but do not flood or waterlog the soil.

Germination should take place within 10 – 14 days for the Weeping grass and within 14 – 21 days for the Wallaby grass during autumn and spring. The seed can take longer (up to 6 weeks) to germinate during colder weather.

Please be patient.

Wallaby grass seedlings are very small and fine when they emerge.

Weeping grass seedlings are wider and flatter then Wallaby grass.

At the early stages of establishment keep broad leaved weeds under control by hand weeding.

Maintenance:

Once the seedlings reach maturity, the lawn may be cut.

Keep the mowing height above 50mm.

The lawn should only need infrequent mowing, possibly only 6 times per year.

A general lawn fertilizer can be applied at 3 months and then only occasionally, if at all.

Sowing a Redgrass Lawn

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Sowing a Redgrass Lawn

Redgrass is a strong grass with a moderate to fine texture, suited to lawn and turf. It is suitable for the drier and semi-arid inland areas of temperate Australia.

This grass is a summer growing perennial which is dormant during the winter months when it takes on a reddish tinge. It grows best on cracking clay soils of low fertility.Redgrass has excellent tolerance to high temperatures and drought with above average tolerance to shady situations.

Sowing:

Native grasses do not like competition from weeds as they have relatively slow growth rates, so ensure the soil is well prepared and weed free prior to sowing.Redgrass-seedling

Sow the seeds in early spring through to early autumn when the soil is moist for best results. Sow the seed close to or on the surface, and lightly rake over to ensure that all seed is in good contact with the soil. We recommend at least 1 kg of pelletised seed to cover 100 square metres.

Watering may be necessary to aid germination if rainfall is sparse.

Germination occurs when air temperatures are above 25˚C and seedlings should emerge in 7 – 10 days. Once germinated the plants can survive and develop for many weeks without irrigation or rainfall.

Please be patient.

At the early stages of establishment keep broad leaved weeds under control by hand weeding.

Maintenance:

Allow the seedlings to thicken up before mowing.

When they are well established, keeping mowing heights to 25mm. The lawn should only require mowing if seedheads shoot in summer and then once or twice per year should be sufficient.

Redgrass does not require fertilizer.

Sowing a Wallaby Grass Lawn

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Sowing a Wallaby Grass Lawn

A Wallaby grass lawn is fine textured, hardy and drought tolerant.

We sell 2 different varieties of Wallaby grass suited to lawns:

  •  Hume Wallaby grass
  •  Oxley Wallaby grass

Wallaby grass is a cool season perennial grass which grows naturally in the temperate areas of eastern and south western Australia. It grows on clay loam to light sandy soils. Wallaby grass has above average tolerance to high temperatures. While predominantly a cool season grass, Wallaby grass will usually stay green during the summer months. Wallaby grasses are tolerant of cold and frost and will grow in shady situations.

Sowing:Oxley-Wallaby-14-days

Native grasses do not like competition from weeds as they have relatively slow growth rates, so ensure the soil is well prepared and weed free prior to sowing.

Sow the seeds between autumn and spring when the soil is moist for best results. Distribute the seed evenly over the soil surface, lightly rake over to ensure that all seed is in good contact with the soil.

Keep the seed moist until the seedlings are established, but do not flood or waterlog the soil.

Germination should take place within 14 – 21 days during autumn and spring. The seed can take longer (up to 6 weeks) to germinate during colder weather.

Please be patient.

Wallaby grass seedlings are very small and fine when they emerge.

At the early stages of establishment keep broad leaved weeds under control by hand weeding.

Maintenance:

Allow the seedlings to thicken up before mowing. When they are well established keep the mowing height at a minimum 40mm for an Oxley lawn and 50mm for a Hume lawn.

The lawn should only need infrequent mowing, possibly only 6 times per year.

A general lawn fertilizer can be applied at 3 months and then only occasionally, if at all.

Sowing A Griffin Lawn

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Sowing a Griffin Weeping Grass Lawn

Weeping grass is native to Australia and makes an attractive lawn similar in appearance to introduced Bluegrass or Ryegrass.

Griffin Weeping grass is a specially bred low growing form of Weeping grass which makes it ideal as a turf grass. It is versatile as it has above average tolerance to high temperatures and frost, and above average to excellent drought tolerance. Its other main advantage is that it is shade tolerant.

Sowing:

Sowing Griffin LawnNative grasses do not like competition from weeds as they have relatively slow growth rates, so ensure the soil is well prepared and weed free prior to sowing.
Sow the seeds between autumn and spring when the soil is moist for best results. Sow the seed 10 – 15mm below the surface, or if spread over the soil surface, lightly rake over to ensure that all seed is in good contact with the soil. We recommend at least 1 kg of seed to cover 100 square metres.

Keep the seed moist until the seedlings are established, but do not flood or waterlog the soil.

Germination should take place within 10 – 14 days during autumn and spring. The seed can take longer (up to 6 – 8 weeks) to germinate during colder weather.

Sowing Griffin Lawn Weeping Grass

Please be patient.

Weeping grass seedlings are about 2 – 3mm wide and tend to lie flat.

At the early stages of establishment keep broad leaved weeds under control by hand weeding.

Maintenance:

Allow the seedlings to thicken up before mowing.

When they are well established, keeping mowing heights between 25 – 40mm. The lawn should only require mowing about 6 times per year.

If there are any thin patches in the lawn, Weeping grass will spread very slowly to fill these in. It has short rhizomes under the soil which grow out to produce new shoots. Weeping grass is not invasive like Couch, Kikuyu and Buffalo grass. Alternatively thin patches may be oversown later.

Weeping grass lawns may benefit from an occasional feed of lawn fertilizer, particularly if the lawn begins to show tinges of yellow.

Griffin Weeping grass is a very low maintenance grass which lives for a long time. It may brown off during very hot, dry periods but doesn’t die, unlike other introduced lawn grasses. This is great advantage as even a slight shower of rain will see it green up again and occasional watering with grey water will maintain it during summer.

Griffin lawn

7 Steps to successfully sowing native grasses

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7 Steps to successfully sowing native grasses

  1. Sow seed into a weed free bed
  2. Good soil preparation
  3. Sow the seed at the right time of year
  4. Sow the seed at the correct depth
  5. Water
  6. Maintain good weed control
  7. Be Patient

Having a successful establishment of Australian native grasses is not really difficult. There have been many failures in the past resulting in prejudice. However, it is most likely that this has been the result of a number of factors;

  • poor seed
  • poor knowledge of germination requirements
  • assumptions about the desired conditions for germination Using incorrect sowing times and depths combined with poor quality seed will inevitably lead to failed results

In the past high quality seed has not been readily available. Remnant stand harvests are not reliable as purity and germination percentages are often low. A recent test by Native Seeds of some Wallaby grass harvested from a remnant stand showed not only around 15 other species included, but also only a 4% germination of the Wallaby grass present. Good knowledge of the ideal germination conditions has not been widely available and is only now becoming more widespread through groups such as the Stipa Native Grass Association and the SA Native Grass Resources Group.

It is often assumed that as native grasses are very hardy and able to withstand drought and other hardships that the seed will be able to establish on hard, dry soils with no attention whatsoever. Unfortunately this is not the case and our grasses require every bit as much attention as the exotics.

Indeed for many of our grasses seedling recruitment is a relatively rare event and only occurs when conditions are absolutely perfect. This may be as infrequent as one year in ten when the lucky co-incidence of plentiful rainfall, appropriate temperature and sunlight are able to promote a flush of germination of the desired grass.

There are a number of factors that contribute to a successful result when sowing native grasses.

1. Have good weed control prior to sowing

Native grass seedlings are slow to establish and will not compete well with many exotic weeds which establish far faster and spread more rapidly.

2. Have good soil preparation at sowing

The better the soil to seed contact that is maintained, the higher the rate of germination of seeds. So a fully prepared seedbed will always give higher establishment rates than an unprepared or partially prepared seedbed. Even if the area being sown is very small, then a well prepared seedbed will yield better results

3. Sow them at the most suitable time of year

For all species there is an optimum temperature for establishment. It varies from species to species but usually it is from autumn to spring for cool season species and from spring to early summer for warm season species. The exception to this comes when irrigation is available as this then allows the sowing of cool season species in summer (albeit with much more effort). The key factors we have found are firstly, to sow the cool season species when moisture can be guaranteed to remain around the seed for 3 to 4 weeks after sowing, and secondly, for warm season species to focus on times when temperatures are above 25oC and try to provide a wet-dry-wet watering regime with pronounced periods of dry soil conditions.

4. Sow with appropriate equipment

The most suitable equipment is that which sows the seed to the preferred depth (usually 10 to 15 mm or about œ inch) and which can meter it out regularly and evenly. With our new pelletized seed becoming available almost all pieces of conventional equipment can sow native grass seed successfully.

5. Apply irrigation if necessary

This might seem odd for native grasses, but they do respond to irrigation or rainfall at appropriate times. It may be that for some high value jobs it is best to establish the native grasses with temporary irrigation systems that are removed once the grasses become established.

6. Maintain good weed control through the early seedling stages of growth

As stated earlier native grass seedlings are not usually strong competitors against weeds. They are normally tolerant of broadleaf herbicides once they reach the 5 leaf stage so this method can be used for broadleaf control. Grass weeds can be more difficult, but the slow growth rate of the natives can be of some benefit here as wick-wiping of the taller growing exotics can be quite selective and mowing to remove the seedheads of annuals can reduce the number of seedlings in the following year.

7. Be patient

Please be patient. These grasses are wonderful long-term competitors once they are established, but are slow to get established and have many slow growth stages during their development. Frustration will set in at various times, but if you can be patient, the results will be there.

Carbon storage

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Carbon storage – native vs. introduced grasses for carbon storage

What effect does carbon have on the environment?

Carbon pollutes our air, increasing the greenhouse effect or global warming. Temperatures are said to rise. Polar ice caps said to melt. But it also plays a detrimental role on the environment and our own health.

So what does this have to do with grasses?

Just about everyone knows that trees store carbon. But did you know that grasses also play a major role in carbon storage?

Ok, so why native grasses and not just any grass?

When trees break down, either rapidly in a fire or slowly through death and decay, the carbon that was in their foliage is returned to the atmosphere. Thus tree carbon is only a relatively temporary solution to carbon sequestration.

When grasses die, the leaves decompose and also release carbon back to the atmosphere. So the selection of long-lived grasses is important if your aim is to provide a long-term carbon sink. Clearly native grasses are highly persistent in their natural environment and are a natural choice for this purpose.

Ok, ok? so what does this have to do with me?

Well, possibly nothing or possibly a lot. We just hope that with this valuable nugget of information, you will at least consider (or continue to consider) native grasses as an alternative to the cheap, low quality introduced grasses that can actually be harmful for our environment both in terms of carbon and in terms of fuel load for fires (which you learn more about from Bob Myers in this video).

If you have any questions, please don’t hesitate to call us on 1300 4 73337 or email to enquiries@nativeseeds.com.au !

Infrastructure Projects

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Rehabilitate Soil Exposed by Infrastructure Projects

Infrastructure projects, should be rehabilitated immediately. Otherwise, the area will be more prone to erosion. Excessive amounts of dust could be a problem, too.

However, restoring such sites to their original condition can be quite a challenge. As you may know, it took native grasslands thousands of years to develop and reach an extensive coverage. Therefore, it is essentially impossible to ensure their complete reproduction in just a very short time. But don’t be disheartened. There are steps you can take to start rehabilitating areas affected by Australian infrastructure projects.

Instead of using introduced grass to cover soil exposed by major land infrastructure projects, it’s best to sow native grasses because they will growin poor conditions and are much easier to maintain. They are considerably cheaper, too. When choosing a seeding mix, it should include rapid establishing grasses such as Windmill grass (Chloris truncata) and Wheat grass (Elymus scaber), as well as slower establishing species such as Kangaroo grass (Themeda triandra) and Wallaby grass (Rytidosperma spp.) for many areas of Australia.

OLYMPUS DIGITAL CAMERA

If the site is highly prone to erosion, or if you need to see fast results, a cover crop of a cereal like Ryecorn or Japanese Millet can be sown at 20kg/ha along with native grass mix. They will die off within a few months, but their root system will help hold the soil together and protect the emerging native grass seedlings. ou just need to make sure that the cover crop does not drop seeds on to the ground.

Weed control is also important during the initial stages of the rehabilitation process. Weeds need to be controlled. Otherwise, they could smother the emerging native grass seedlings and steal valuable nutrients from them.

Need help rehabilitating areas affected by infrastructure projects? Contact us at Native Seeds anytime. We can provide you with quality seeding mixes that can help revegetate exposed soil.