BOOK XVII. xiv. 74-xv. 77
that day and that day only it is dangerous for them if there is the smallest sprinkle of rain or a breath of wind; whereas for the future the plants are continually safe and secure, and later on they have a dislike for humidity. Jujube-trees are also grown from seed sown in April. Tuber-apples are better grafted on the wild plum, the quince or the buckthorn bush,ᵃ the last being a wild thorn. Any thorn also takes grafts of the sebesten-plum extremely well, and also takes the sorb-plum satisfactorily.
As for the recommendation to transfer plants from the nursery to some other place before they are planted out in the place assigned to them, I consider that this causes unnecessary trouble, albeit this process does guarantee the growth of leaves of a larger size.
Growing and planting elms, poplars and ash-trees.XV. Elm-seed should be collected about the first of March, before the tree is clothed with foliage, when the seed is beginning to turn yellow. Then it should be left in the shade to dry for two days, and afterwards thickly sown in ground that has been broken up, and a layer of earth sifted fine in a sieve should bc sprinkled on it, § 73.of the thickness recommended in the case of cypresses; and if no rain comes to your assistance, it must be watered. A year afterwards the plants should be removed from the rows of the beds to the elm-grounds and planted at a distance of a foot apart each way. Atinian elmsᵇ it pays better to plant in autumn, because they are grown from cuttings, having no seed. For a grove in the neighbourhood of the city they should be transplanted when they are five years old, or, as some hold, when they have reached a height of twenty feet. They should be set in what is called a 'nine-square foot' trench, 3 ft. deep and
