Merritt’s Hydrangeas ‘Bloom 
Hydrangea Culture 
OUR SPECIALTY—We are Hydrangea Specialists, grow- 
ing no other Flowers or Plants. We do not force Hydrangeas 
into flower, but concentrate all of our efforts to produce better 
Hydrangeas for you to bloom. We ship rooted cuttings and 
small plants, in season in all varieties, for growing on, and 
dormant Hydrangeas in the Fall and early Spring for forc- 
ing. We force some of every variety, each year, for a culture 
check, and they can be seen at our Greenhouses during the 
early Spring months. 
VARIETY SELECTION—First, make sure of the varieties 
that grow best for you and that sell best in your locality. 
Try a few novelties each year to see how they act under your 
conditions, but stick to the proven varieties until you have 
found a better one. If in doubt, as to variety, please specify 
your selection early, midseason or late, and we will give our 
very best judgment from our past experience giving the best 
varieties for your locality. 
If you propagate your own, do not make the common mis- 
take of rooting all of the blind shoots that appear. Remember 
that “Like begets Like” and if this practice is followed, it 
will eventually lead to disaster, and one day you will find a 
complete crop of blind Hydrangeas. Rather than that, keep 
varieties separate and select the very best flowering plants 
and get your cuttings from these by sacrificing the flower 
tips. It will pay dividends. 
SOIL—tThe soil for potting should be low in nitrogen, par- 
ticularly so with leafbuds, but should contain phosphorus, 
potash and calcium. A good mixture consists of two parts 
loam, one part of peat and one part of well rotted manure. 
If the original soil is very heavy, some sand may be added. 
Include a four-inch potful of superphosphate and a 2%-inch 
potful of muriate of potash and the same amount of calcium 
sulphate (gypsum) to a wheelbarrow of soil. Complete fer- 
tilizers which contain nitrogen should be added later upon 
repotting. Keep the Ph of the soil about 6:0. 
SHIFT—Shift the plants from two- or three-inch in which 
they were potted directly into five- or six-inch pots and place 
these outdoors, after danger of frost, in the Spring. This is a 
better method than planting directly in beds. In regions of 
extreme heat, a lath house or a covering with snow fence is 
very desirable. Such half shade develops large foliage, par- 
ticularly if additions of ammonium sulphate are made about 
every two weeks, used as a liquid at the rate of one ounce to 
two gallons of water (three lbs. to 100 gallons). During the 
same growing period two or three applications of such com- 
plete soluble fertilizer as 15-30-15 should be made using it 
at the above rate. This will insure adequate phosphorus and 
potash content. 
Depending on the color of the foliage, iron sulphate should 
be used to correct chlorosis. Use it at the rate of three pounds 
to 100 gallons or one ounce to two gallons. The iron will keep 
the foliage green. It has no bearing on the bluing of flowers 
unless the soil itself contains aluminum which may become 
available as the soil is acidified by iron sulphate. Growing 
in the field and not potting until September is a common 
method but its success depends on adequate rainfall, and 
only moderate heat in the summer. Usually under such a 
treatment most of the growth starts late, when temperatures 
are reduced and much blindless results. 
PINCHING—Pinching should be done from late June to 
mid-July, depending upon the locality and variety. The early 
pinching should be done in the north to produce enough 
growth before buds set in September. Pinch as low as possi- 
ble, leaving two sets of leaves and thus four buds (where 
practical). If plants are well grown (properly fertilized and 
watered), the wood is sufficiently heavy and yet succulent so 
soft pinching is not objectionable. 
SUN & WATER—Depending again on locality, the plants 
under lath should be given full sun (by removing the snow 
fence) from August 1 to September 1. The longer the plants 
are kept under lath the taller they get. The abrupt change 
from half shade to full sun may cause some foliage burn, but 
this is never serious if the plants are sprayed often with 
water. The change will cause the buds to set quickly due to 
the action of full light on the large foliage which will manu- 
facture the food for the buds. 
An adequate watering system, or automatic water lines are 
your best insurance against drought. ‘ 
Earlier pinching is advocated when plants are grown with- 
out cover, particularly varieties like Strafford, Merveille and 
Dundalk. Sufficient growth must be produced by September 
to insure bud set. Pot grown plants are better than those 
planted directly in the fields or beds. Plunge them to reduce 
drying out, but be sure your soil drains well. 
TRIM—During the growing period all weak shoots should 
be removed and the growth concentrated in the number of 
stems you wish to finish. It is best to do that as early after 
the buds develop from a pinch as possible. Again during this 
growing-on period don’t be stingy with water and fertilizer. 
Continue to give adequate water until October but be sure 
that your plants are in a protected frame or cool greenhouse 
before there is any danger of frost. Don’t take chances—even 
though well-hardened Hydrangeas will take a heavy freeze. 
STORAGE—The best place to store hydrangeas from about 
November on is a dark storage where the temperature may 
be kept between 35°-40° F. During this period keep the soil 
moist but don’t overwater. Drying out will shrivel buds. Be 
sure there is a proper circulation of air, to prevent bud drop. 
Spray or dust with “Zerlate” (DuPont) several times, while 
in storage. 
FORCING—Start forcing right after your Poinsettia 
benches have been cleaned out December 20 to 25th. Some 
advocate starting at 50° F. to 56° F. and then raising the tem- 
perature to 60° after about two weeks. Some people have diffi- 
culty in getting the plants to break quickly. This may be due 
to a number of causes. If you buy dormant stock, pot the 
plants in the same size pot as they were grown in. Repot 
when the new roots have started. Furthermore, don’t keep 
the plants so wet that there is not enough air in the soil to 
develop new roots from the dormant ball. If you are grow- 
ing your own plants, again let us warn you about overwater- 
ing at first. There is a sensible limit to the suggestion of 
using lots of water. 
REPOTTING—If you buy dormant plants and wish to save 
the double work of potting in the same size pots and later 
shifting to a large size, be sure that the soil you use is low 
in nitrogen, else you will have trouble. Likewise light crush- 
ing of the dormant ball will help the roots to develop more 
quickly. Add phosphorus, potash and calcium as indicated 
under soil for potting. 
FEEDING—To avoid yellowing of leaves (chlorosis), apply 
the iron sulphate and ammonium sulphate mixture as recom- 
mended previously. This is now during the forcing period. In 
addition apply complete fertilizers (15-30-15 or similar) in 
liquid form two or three times during this period. Or use Elec- 
tra, applied at the rate of a thimble full to a five-inch pot, 
every ten days during the forcing period, until the plants 
show color. Be sure the soil is moist (never dry) when apply- 
ing fertilizer. 
COLOR—To blue Hydrangeas, use aluminum sulphate at 
the rate of one pound to five gallons of water Depending on 
your soil, 3-7 applications may be needed to give the color 
you want. Regular use of iron sulphate, especially where 
water is alkaline, will keep your blues cleaner. 
FINAL FORCING—During the hot days of spring, do not 
permit plants to dry out or serious foliage burn will result. 
At the first sign of wilting, water and syringe. If you see 
signs of scorching due to drying and heat, syringe thoroughly 
and shade. Try to always give some ventilation, and as much 
as possible during the last days of forcing. If possible, reduce 
temperatures during the last two weeks before sale. You'll 
have better color and the plants will last longer in the house. 
a 60° buds should show, in most localities, six weeks before 
sale. 
For Mother’s Day, start forcing in February and follow the 
same general growing procedure. 
INSECTS, MOLD & MILDEW—Keep red spider, thrips, 
aphids down with Parathion aerosols. 
Mildew may be kept in check with Zerlate. 
Always remember, the best Hydrangeas come from the 
earliest cuttings. 
JosepH S. Merritt 
