I went for a walk in a park yesterday. In the first 30 meters, I saw four grasses. These are common grasses to find in parks in Southeast Asia. I took a photo of each grass from above, with a 1 yen coin as a size reference, and also a photo of the typical inflorescence of each species. With a little practice, one can identify these grasses with ease by looking at the foliage and inflorescence.

These grasses are:

• manilagrass (Zoysia matrella 'nuan noi')
• tropical carpetgrass (Axonopus compressus)
• golden false beardgrass (Chrysopogon aciculatus)
• sour paspalum (Paspalum conjugatum)

manilagrass

This is manilagrass. Well, mostly manilagrass. There is a plant of tropical carpetgrass in there too.

The inflorescence with the white flowers is typical for manilagrass. In Southeast Asia, one can usually find the inflorescence in unmown and well-irrigated manilagrass at any time of year.

tropical carpetgrass

This is tropical carpetgrass. The first place I would look for tropical carpetgrass is under trees. This grass is prolific in shade. Tropical carpetgrass has shiny leaves.

This is the typical inflorescence of tropical carpetgrass.

golden false beardgrass

Chrysopogon aciculatus has shiny leaves, like tropical carpetgrass, but the leaves are narrower and shorter.

This grass is also recognized easily by its distinctive inflorescence.

sour paspalum

The leaf width of sour paspalum is similar to tropical carpetgrass, but sour paspalum leaves are pale yellow by comparison, and not shiny.

The inflorescence of sour paspalum is also distinct.

There was another successful shiba yaki (grass burning) ceremony at Korakuen last week.

More about grass burning in Japan in this post.

This was a new one to me. I saw the course laid out at the Ayutthaya Historical Park and thought it looked similar to Park Golf. But where Park Golf involves hitting the ball into a hole, a woodball hole is completed when the ball passes through a gate.

Woodball course laid out on *Polytrias indica* in Ayuddhaya

A photo posted by Micah Woods (@asianturfgrass) on Jan 7, 2017 at 11:03pm PST

This video explains the woodball rules.

Looks like fun.

Korakuen in Okayama is one the three great gardens of Japan, and I like it especially because of its expansive noshiba (Zoysia japonica) lawns. In early February every year, a shiba yaki (grass burning) ceremony is held at Korakuen, when the lawns are burned.

The video above shows the ignition of a lawn. The Facebook page of Korakuen has more photos of the shiba yaki ceremony this year.

It is pretty amazing how strange it looks before the lawns start to grow again.

For more about grass burning in Japan, see:

• When the smoke clears away tomorrow ...
• Thatch control by burning

One of the best places to study tropical grasses in Southeast Asia is at the Suanluang Rama IX Public Park in Bangkok's Prawet District.

The two primary species on lawns at Suanluang Rama IX are tropical carpetgrass (Axonopus compressus) in shaded areas and manilagrass (Zoysia matrella) in open areas.

If you visit the park you will notice that the carpetgrass forms a monostand under the trees, and at the edge of landscaped areas, but moving outside the drip lines of trees into areas that get more sun, the sward transitions to one dominated by manilagrass. In the photo below, one can see, just after sunrise, the manilagrass in the center of the photo holds more dew than does the carpetgrass.

This year in April, a new medicinal plants garden was established in the northern part of the park.

Medicinal plants are interesting, but what I found really exciting when I had a chance to explore this new garden is that there are much more than just medicinal plants there. In fact, there is an extensive grass collection, the largest I have seen in Southeast Asia.

For mown turfgrasses in zone 14 of the medicinal plants garden, one can see:

• 2 types of Zoysia
• 3 types of Cynodon
• Paspalum vaginatum
• Axonopus compressus
• Stenotaphrum secundatum 'Variegatum'

There are more ornamental and forage grasses and grains than turfgrasses -- rice, sudan grass, maize, sugar cane, and scores of others.

One can find common ornamental grasses such as Pennisetum setaceum 'Rubrum', along with a lot that I saw for the first time.

In the new medicinal plants garden one can also find herbs and vegetables, and in other sections of the park there are also vegetable and herb gardens for educational purposes.

A highlight of the year is the Suanluang Rama IX Flower Festival, held from December 1 to 10 each year. I've been to this festival a few times, and the 2015 version seems the best one yet. There are even grass elephants!

These displays of horticultural art during the flower festival are reminiscent of the Girona Temps de Flors. If you can't make it for the flower festival in early December, there are still plenty of other plant collections that remain open year round. The fern and orchid houses are in a deeply shaded section of the park.

But back to the grass. As I mentioned, if you see the lawns at the park, they are primarily composed of tropical carpetgrass, as seen above in front of the fern and orchid houses, and below under the trees.

In some less shaded areas, the primary species is manilagrass. The species composition at Suanluang Rama IX park in Bangkok is the same as I've described for the lawns at the Marukatayawan Palace. One can also find Java grass (Polytrias indica) growing in patches around the park. It is usually, as shown below, found within patches of manilagrass. Polytrias indica has an inflorescence that is russet in color and this species forms a distinctive component of the sward because of this coloration.

One can also find Chrysopogon aciculatus and Paspalum conjugatum mixed in with the Axonopus compressus in some places. The leaf characteristics of those three species are similar, and it is only obvious that all three species are present when the plants are flowering. These grasses on the lawns at Suanluang Rama IX park and in the grass collection of the new Medicinal Plants Garden are typical of the grasses that grow and are used in South and Southeast Asia. Well worth some study if you care about these things.

Even if you don't care much for botany or agrostology or grass elephants, I would still recommend a visit. This is the freshest air in the city and the park is popular for running, walking, cycling, boating, birding, tai chi, yoga, and aerobics.

This afternoon I was at my favorite park in Bangkok, the King Rama IX Park. This park is near my residence and when I am in Bangkok I frequently go to this park in the early morning or late afternoon for jogging. Today I noticed a lot of algae growing in the ponds —see above the clean water amongst the Victoria amazonica lilies and the algae everywhere else — and was reminded of three things I wanted to share about phosphorus, and phosphorus fertilizer applied to turfgrass in particular. 

1. Phosphorus is essential for food production, is a limited resource, and common sense tells us that we should not apply it to turf if it is not absolutely necessary. Earlier this year I read an interesting article in Foreign Policy entitled Peak Phosphorus. The authors argue that "our dwindling supply of phosphorus, a primary component underlying the growth of global agricultural production, threatens to disrupt food security across the planet during the coming century. This is the gravest natural resource shortage you've never heard of."

I can assure you, if there is adequate phosphorus in the soil, adding more will have no beneficial affect to the turf. How can you tell if phosphorus is necessary? By a routine soil analysis. I use 35 parts per million (ppm) phosphorus on a Mehlich 3 soil test as a conservative threshold level for deciding whether phosphorus fertilizer is required or not. If you are applying fertilizer without doing a soil test, you are probably wasting money and over-applying phosphorus. And if you are applying phosphorus fertilizer to turfgrass growing on soil that has 35 ppm phosphorus or more, you may as well shred money and apply that to the grass. The effect on the turf will be the same.

2. Back to the algae in the water at the Rama IX Park, that algae would not be growing if there was not phosphorus in the water. Phosphorus is usually the limiting factor in algal blooms (eutrophication) of water bodies. Adding phosphorus to turfgrass when that phosphorus is not needed will increase the risk of polluting nearby water bodies and will have no effect on the grass.

3. People ask me how to prevent algae from growing on putting greens. There are a number of techniques to employ, but an essential one is to avoid unnecessary applications of phosphorus. Dr. John Kaminski, Director of the Golf Turf Management Program at Pennsylvania State University, has done research on creeping bentgrass turf during summer conditions to evaluate the effect of different fertilizers on algae. In summary, the results have shown that applying nitrogen only (particularly ammonium sulfate, 21-0-0) prevents algae, while adding phosphorus causes a tremendous increase in algae. From a paper Kaminski published in the International Turfgrass Society Research Journal, there was no algae (0%) in plots fertilized through the summer with ammonium sulfate. A complete fertilizer containing phosphorus (20-20-20) always had algae and in some cases more than 20% of the surface area was covered by algae rather than grass. If you often have an algae problem on your greens, you may want to reevaluate your phosphorus fertilization program.

P.S. At the time I wrote this post in 2010, I was using 35 ppm for P. After the development of the MLSN guidelines, I use them instead, and as of 2016 I'd work with a minimum P level by the Mehlich 3 test of 21 ppm.