Purchase well-grown, heavily rooted, one-year-old plants of all fruits except blueberries and brambles. Two-year-old blueberry plants are recommended. Nursery plants listed as "certified" (true to name) and "virus tested" or "virus indexed" are recommended. Brambles and stone fruit trees (peaches, nectarines, plums, cherries) are especially prone to virus infection in the nursery. Infected plants are not very vigorous and may produce little fruit, so it is worth the additional cost to buy virus-tested plants. Micropropagated ("tissue-cultured") brambles should be multiplied and grown in a greenhouse in steam-sterilized soil. Any bramble plant that has been grown outside in a nursery may be infected with several diseases, all of which will result in poor plant growth and yield.