Lawn Care - Solving The Weed Problem
( Originally Published 1906 )
No room for weeds on a well kept lawn—Guarding against infection—The commonest pests—Digging out dandelions and plantains—Poisoning the root—Sour grass and moss—Lime the remedy—The pestiferous crab-grass—The friendly frost—Bermuda grass in the North—Fall grasses—Fall weeding best—Poultry manure vs. weeds —Ants—The white grub—Earthworms—Moles—Fairy rings and other fungi.
UNLESS a lawn is maintained in its highest efficiency, and the growth of the grass continuously stimulated, weeds will creep in. The surest method of keeping out the undesirable growths among the grass is by keeping the good growth thoroughly occupying the ground. As sure as the desirable lawn grasses are allowed to die out, undesirable, rank growing weeds will immediately occupy the ground—nature abhors a blank spot.
Where such weeds have secured a foothold, they should be dug out by one of the convenient hand tools, going over the ground most thoroughly in the spring time and persisting in the work as long as the plants show any tendency to active growth, and on no account must they be allowed to run to seed. So far as possible neighbouring uncultivated patches which have become a prey to common weeds should be roughly mowed over with the scythe two or three times during the year, or they may be burnt over. In fact almost any means is justifiable in order to reduce the chances of infection by weed seeds. The most common pests of the lawn are the dandelion, the plantains, dock, crab-grass, Bermuda grass (in Northern lawns), wild carrot, chickweed, sorrel, and moss.
DIG OUT THESE WEEDS
The dandelions, plantains, and dock must be cut out, root and all. It is no good to merely crop off the rosette of leaves without digging into the soil and taking out as much of the root as possible. Indeed, very often the mere chopping off of the rosette will result in an increase of the number of crowns later in the season. When digging the roots out of the lawn, the worker may at the same time repair the damage by treading the surface till the hole is closed. Where bad patches have occurred, resulting in ugly, large sized holes, fill in with a little good quality garden loam, scattering a pinch or two of lawn seed mixture and beating the surface well with the back of the spade.
Dandelions may be eradicated from lawns at relatively slight expense and without material injury to the grass by spraying with a solution of iron sulphate. Four or five applications are necessary; the first of May, one or two should follow at intervals of three or four weeks, and one or two more in late summer. A conspicuous blackening of the lawn follows each application, but this soon disappears if the grass is in a vigorous and healthy condition. The spray solution is prepared by dissolving one pound of iron sulphate in each gallon of water. The quantity required is approximately 4 lbs. to a thousand square feet of lawn, or 175 lbs. to the acre. It must be prepared in wooden or earthen-ware vessels, as it is highly corrosive to metal.
Plantains are more easily dug out than dandelions. They cannot be made use of in any way, but they will seed very freely and soon become a pest on the untended lawn.
They show a great tendency to occupy soil of a somewhat heavy nature, especially one that is insufficiently drained. The work of removal should be accomplished in the early spring before the plants have come into flower. There are two species of plantain which are sufficiently well known, the one having narrow leaves six to seven inches long and half an inch wide, commonly called rib grass; the other having shorter, much wider leaves, strongly marked with the parallel veins or ribs. The plantains make a strong root, but do not penetrate so deeply as the dandelion. They throw out more lateral rootlets which are strong and wiry, and generally it is necessary to make a pretty wide cut in order to remove the plant properly.
If it is not convenient to cut out the entire root they may be killed, after the crown has been removed, by poison. A crystal of sulphate of iron (green vitriol) placed on the top of the cut surface will dissolve and kill the root which is left behind. Such treatment, however, is not generally recommended, as there is danger of strong corrosive chemicals doing damage to the grass roots by spreading in solution in the soil and necessitating very extensive repairs by turfing or reseeding. A drop or two of gasoline is said to be effective.
THE RESULT OF SOUR SOIL
Soir grass (or sorrel) and moss are pests on many lawns and are sure indicators of unsatisfactory ground conditions. The lawn which has become infested with these weeds is in all probability sour and badly drained. The easiest immediate remedy is by winter dressings of air slacked lime at the rate of one bushel to a thousand square feet of lawn. Better, however, it would be to underdrain by sinking lines of tile. Land can be over-drained, an extreme which must be avoided, and for which it is not possible to lay down any definite rules. It is a matter of judgment, and, generally, some good idea of the number of drain ditches that should be put in can be ascertained from some local farmer or gardener who has had experience with the soil of the locality. Bottom lands will always need more drainage than up-lands. The advantage of attacking these weeds by a surface dressing of lime is especially marked on a blue grass lawn as the grass will make a much more vigorous growth in the presence of the lime. It is possible, indeed, to maintain the lawn in very good average condition by annual dressings of lime in the quantity here advised.
THE WORST WEED OF ALL
Crab grass (Syntherisma or Panicum sanguinale) is the worst weed enemy of the lawn. It creeps over the surface in such a way that it is untouched by the lawn mower, yet a strenuous fight must be waged against it as soon as its presence is recognised. It is an annual and will reseed itself year after year unless it is attacked and actually pulled out. The seeds germinate in June and early Au-gust and its unwelcome presence in the full summer season mars what may be otherwise a good lawn, by its broad pale green leaves, which give a very patchy and unhappy appearance to the general surface of the grass. As soon as the cold weather approaches the creeping stems of the crab grass change to a bronzy red colour, which becomes more and more intense as the cold increases, making the lawn in the latter part of the season look quite "rusty"; which no amount of watering will revive into bright green. The first touch of frost spells death to the crab grass, but there is little satisfaction to be de-rived from that fact. Where it is killed the lawn is left with unsightly brown patches which are open to the inroads of weeds and there is always the certainty that the plant has infected the lawn with its own seeds for another year's crop.
There is only one practical method of attack, and that is both costly and burden-some. As soon as the grass begins to spread, take a sharp-toothed garden rake and yank up the creeping stems of the crab grass, pulling them clear from the surface of the soil and leaving them spread on the top of the regular lawn surface. If the lawn mower with knives set very low be now run over the ground the flower heads will be cut off, which will pre-vent the seeding. If this is not done during June and July the low creeping stems will by the end of August have successfully crowded out and killed many cd the more desirable grasses. It is no use to merely run the mower over the lawn without previously pulling up the creeping stems in the way described, for the machine will then simply cut the leaves, actually stimulating the stalks below to further growth and tighter rooting into the ground. Rolling with a three-thousand-pound machine has killed crab grass in Philadelphia.
OTHER WEED GRASSES
Bermuda grass (Capriola, or Cynodon, Dactylon) is objectionable in Northern lawns merely because it becomes discoloured on the first touch of frost, leaving ugly brown patches. Of itself it is not otherwise undesirable. In a blue grass lawn this patchiness toward the end of the season is very undesirable, and the Bermuda grass may therefore be classed as a weed north of Washington. South of that city and especially upon the sandy soils of the Atlantic coast Bermuda grass is the main dependence for lawns.
As the fall approaches, orchard grass (Dactylis glomerata) is likely to make its appearance in many lawns, so is timothy (Phleum pratense). They may even come in accidentally with low grade lawn mixtures. Wherever they appear they should be ruthlessly dug up; in fact no strong growing bunch or tuft grass should be tolerated for an instant. They should immediately be dug up, lawn grass seeds scattered on the bare spot, and the soil firmed down with the back of the spade.
WHEN TO DIG WEEDS
It is better to dig out these rank growing weeds in the fall, rather than in the spring, as their removal in the early part of the year opens up a quickly-seized chance for crab grass to gain a foothold, especially during the hot weather which may be expected from the middle of May onward. Very often the regular grasses of the lawn are burned out about this time, and it is well not to give too much leeway for the crab grass which germinates in June. The lawn should be in better condition by the end of October than it was in April.
From time to time, varying in different parts of the country and on different soils, hosts of other plants will gain entry to the lawn as weeds, but the foregoing are the more common pests which occur generally. These other weeds are more or less shallow rooting and may generally be eradicated by encouraging a growth of the regular lawn grasses.
In other words the best way to keep out weeds is to keep in grass. The well maintained lawn which is properly cared for in the early spring and which receives an annual top dressing of some fertiliser as already described will not, under ordinary conditions and in ordinary seasons, be seriously menaced by weeds. When a wet, warm summer occurs many other plants may become very bothersome weeds. Chickweed may be taken as a sample. It will then overrun the grass, and must be raked out.
Clover is not generally regarded as undesirable on the lawn (indeed it is usually seeded over in order to get a quick green effect), and many people advocate its presence because its low growing foliage leaves the newly cut lawn with a fresh green colour which would not be the case if the bare stems of the grasses alone were seen. It grows below the level of the lawn mower as generally set, and does not interfere with the growth of the permanent grasses.
A USE FOR POULTRY
The suburban gardener who keeps poultry has at hand a very simple method of eradicating weeds from his lawn. The manure from the poultry house can be saved and composted and spread over the lawn in the fall. This can be put on as thickly as convenient and will have a very stimulating effect upon the growth of the grass in the spring; so strong will the growth be that the weeds will be crowded out of existence. Hen manure to be used in this way should be gathered daily during the season, mixed with an equal quantity of earth or plaster, and stored in a dry place until wanted for use. A dressing of a bushel to a thousand square feet of surface will not be excessive.
INSECTS THAT BOTHER MOST
Perhaps the most troublesome of the minor insects are the red and black ants. These are not usually serious pests on other than light dry sandy soils. With a properly pre-pared site, in which a due proportion of clay has been incorporated, ants will very rarely occur. The chief injury they render is by the manner in which they loosen up the soil around the roots of the grasses. They do not directly attack the plants themselves; but, by loosening the ground in making their tunnels and galleries, the effect is that the roots become dried out and the tops naturally suffer.
The most effectual means of attack is to poison the ants by means of bisulphide of carbon. The work can be quickly accomplished and though not a particularly pleasant operation, it is not so objectionable that there is any excuse for avoiding it. The bisulphide of carbon is a heavy, colourless, volatile liquid which easily sinks into the ground, and the fumes, which are heavier than the air, quickly penetrate downward into the most remote corners of the ants' runs. One or two table-spoonfuls of the liquid may be carefully poured into the opening of the nest and a damp cloth or a handful of soil should be immediately put over it and packed down tightly. Nothing else is necessary. If one application does not entirely rid the lawn of these little pests, it is a simple matter to repeat the attack.
One word of caution is well in reference to the handling of this poison. It is highly in-flammable, and the vapour is dangerously explosive. Be very careful, therefore, not to use bisulphide of carbon in the presence of a naked light, or in the neighbourhood of a fire.
It is sometimes recommended that, after pouring in the liquid and allowing it to vapourise a short time, the covering should be lifted and a match applied to explode the nests. While this may be done, and will be effective in killing the ants, yet it is entirely unnecessary and may even be detrimental to the general condition of the lawn otherwise, inasmuch as the shock of the explosion will aggravate the loosening of the soil around the roots. After the treatment with the bisulphide of carbon, say in the course of two or three hours, the lawn should be copiously watered after rolling with a heavy roller.
A similar treatment may be applied for any other insects that are found sneaking in the lawn.
The white grub of the June beetle will occasionally gain a foothold in untended lawns, especially those that are insufficiently mown. This pest burrows into the ground and feeds on the roots of the grasses, causing very serious damage and often resulting in the entire killing out of the plants. When patches of brown occur on a lawn in summer the presence of the white grub may be suspected. These grubs live in the ground three years be-fore emerging into the perfect insects. They may be brought under control by ploughing in fall and allowing chickens to forage on the lawn, as they are particularly fond of these fat grubs. On lawns which cannot be ploughed up, sprayings with kerosene emulsion has been found a good remedy. The use of a very heavy roller has often been satisfactory in crushing the grubs in light soils.
EARTH WORMS AND THEIR CASTS
Earth worms are an indication of an improperly drained top soil, or of a soil that is cold or heavy. They rarely occur in trouble-some quantity on good mellow soils which are warm and abundantly underdrained. As a matter of fact, their presence would be taken as a very index to the fact that the soil lacks humus. They are nature's most efficient agents in transforming a cold tight soil which lacks humus, and is therefore somewhat unresponsive in cultivation, into a soil that is warmer and generally better adapted for plant growing. They are kept out of tennis courts by providing ample drainage some considerable distance below the surface—by means of a layer of coal ashes for instance. They will not work up through such a material. If they are especially troublesome —which will be manifested by the number of casts thrown up all over the surface of the lawn—the best immediate remedy is to water with lime-water, made by dissolving lime and allowing the liquid to settle and clear. The upper portion may then be used through an ordinary watering can. If a good application of lime water is made in the evening when the work of the worms is especially troublesome, they will be drawn to the surface, and can be brushed or raked up early the next morning. Worm casts must be brushed off the lawn before rolling, otherwise the grass will be killed by the cakes of compact earth. Other suggestions for dealing with worm casts will be found in Chapter XIII.
The most bothersome animal pest is the mole. Tunnelling under the ground, working chiefly by night, a few of these animals, will in a very short time completely mar an otherwise handsome sward. Not only do they make tunnels, the tops of which are likely to fall in with a very slight pressure, but in the course of their travellings they will, at frequent intervals, throw up hills of soil, giving the surface of the lawn an irregular, hummocky contour.
Moles are not seriously troublesome on well rolled lawns. They will always choose a line of least resistance, and a lawn which is kept well rolled presents an entirely too compact mass for Mr. Mole's comfort in travel. If moles are running through a lawn they should be fought by means of mole traps, which are plunged into the runs and usually catch the animals in the night time. Wherever their presence is detected the course of the tunnel should be followed out, and the earth well tramped down. Poisoned bait has sometimes been used with more or less reported success but from the fact that the mole is essentially a carnivorous animal, it is not exactly plain why it should be easily trapped by poisoned grain seeds. The animal does certainly gnaw the roots of plants, but it does this chiefly because they happen to come in his line of travel, and though he may at times, and under special conditions, take to a vegetarian menu, it is not purely the nature of the beast.
FAIRY RINGS AND OTHER FUNGI
Very common in lawns made in a wood-land country is the peculiar growth of the fairy ring fungus. By the time it attracts attention the area of growth of the fungus has usually assumed the form of a hollow circle, the band in which the fungus is developed varying in width from six to twelve inches. This method of growth never fails to excite interest and has been indeed the basis of much legendary lore of the Old World. Starting from a central spot the mycelium of this fungus spreads evenly outward in all directions, seemingly exhausting the qualities of the soil for itself as it travels, and consequently, as it dies in the centre and is always growing on the outer margin, the mature spore-bearing fruits take the appearance of the characteristic, ever widening circles. The fairy ring fungus is not actually injurious to the grass; indeed the growth of the grass in the immediate neighbourhood of the fungus is usually very markedly vigorous. Dressings of lime will assist in controlling the spread of the fungus, which certainly is disfiguring.
Rarely there occurs over the lawn a peculiar slime fungus which seems to spread over extensive areas of grass in a single night. Actually it is not parasitical on the grass, and only appears during specially wet seasons. Its presence is first recognised by an irregular patch on the lawn, maybe measuring several feet in each direction, in which every blade of grass, every grass stem, everything in fact within its area, becomes covered with small slaty-gray globules about the size of a pin's head, which on being ruptured emit a soot like powder. The appearance of this slime mold usually disconcerts the gardener, but he may rest at ease. It will disappear almost as quickly as it came, and even though it spreads over the greater portion of the lawn it does no actual damage to the grass. The slime mold fungi spread over anything that happens to come in their way, and in travel-ling over the surface of the ground swarm upon the grass leaves by accident. It might be well, as a precautionary measure, to give a slight spraying with half-strength Bordeaux mixture.
Various other fungi may from time to time be found growing among the grass, and are generally the fruits of neglect or improper lawn conditions. Occasionally, however, the field mushroom will spring up in a lawn heavily dressed with stable manure, gaining its foothold as a consequence of that very treatment. The fairy ring fungus is also a dainty morsel for the epicure, and is the real "champignon" of the French gourmet.
SUMMER TIME BROWN PATCHES
Because they come in the summer time dead patches of grass commonly attributed to the summer drought are in reality caused by a fungus which attacks the grass and finds congenial conditions during hot, muggy weather on ground which is kept too moist by heavy sprinklings (or insufficient drain-age). The remedy is frequent light sprayings of Bordeaux mixture—not heavy enough to really wet the ground. Blue grass in the North, and Bermuda grass in the South are, however, not attacked by this fungus.