Brown leaves on a gardenia plant can indicate several issues, including environmental stress, improper care, pests, or diseases. Some random examples: Overwatering or underwatering can lead to brown leaves on a gardenia. The soil should be well draining and acidic. Water the soil if dry at a depth of 4 inches; skip watering if the soil is already soggy. If the soil is too compacted, it can lead to nutrient deficiencies and brown leaves. Gardenias can be persnickety and sensitive to many environmental changes leading to leaf yellowing/browning, such as high/moderate temperature fluctuations, sudden and different exposure to direct sunlight after moving it, etc. Exposure to hot, to dry air or to cold winter drafts in winter can cause leaf browning (it may help to keep the soil mulched and moist in winter -especially when frosts approach with lows below freezing- as long as temperatures are above freezing and the soil does not freeze). Deficiencies in some soil nutrients can also cause yellowing and browning of leaves; a soil assay may be needed to determine if your soil has nutrient deficiencies or toxicities. Pests such as aphids, scales, mealybugs, or spider mites can infest gardenia plants and cause damage to leaves, leading to browning so monitor the foliage throughout the growing season. Fungal diseases such as leaf spot can also cause brown spots on the leaves.
The best time to move a gardenia plant is during its "dormant" season, typically in late winter or early spring before new growth begins. But you can also move them in early spring. Before digging up the gardenia, prepare the new planting location. Water the gardenia thoroughly a day or two before transplanting. Moist soil will help hold the root ball together during the move. Using a shovel, dig a wide circle around the gardenia, going at least 12 inches deep to minimize root damage. Try not to disturb/damage the roots. Gently lift the gardenia from the ground, trying to keep the root ball intact. If the plant is too large to lift, you may need to slide a tarp or burlap underneath to lift and carry it. Place the gardenia in the center of the hole at the same depth it was previously planted. Backfill the hole with soil, gently firming it around the roots to remove air pockets. Keep the soil consistently moist (but not waterlogged) at a depth of 4 inches, especially during the first few weeks after transplanting or when hot in its first summer to help the plant establish itself. If the soil is already soggy before you irrigate, skip watering. Apply a layer of organic mulch of about 3 to 4 inches around the base of the plant to help retain moisture and suppress weeds.
Parts of branches that do not leaf out can be pruned to live wood by the end of May or in June.
